Home

CX50 JR Owners Manual

1. 23 Parts Engine Clutch and Kick Lever 24 Pans Engine W Aler EEN 26 Farts ecngdine TOP ENO EE 27 PaltS Exhaust SYSTEM t a 28 Parts Forks Triple ClatmpS 29 Parts Forks Leg Assembly Brake de 30 Parts Forks Leg Assembly Non Brake Side 32 Parts Frame Mounting Hardware 34 Parts Frame Mounting Hardware ll 35 raris 36 37 EE 38 Parts REAL TEE 39 EE 40 Ki Ce Lee 41 PASE 210164623 e Ciel 42 PASE Swingarm PAS SOI MOY 43 44 A 44 Base Gasket Selection 45 area An Le EE 47 Complete Engine Disassembly Procedure 47 Top End Disassembly Procedure 48 SPINNE cT m 4
2. PART DESCRIPTION 1 ECCJO001 CYLINDER INCLUDES PISTON RINGS PIN 8 CLIPS 2 27 00011 BASE GASKET 0 25mm THICK 222 ZCKG0501 BASE GASKET 0 40mm THICK STANDARD 2 ZCMUO0706 GASKET 0 60mm 222 ZCMUO708 BASE GASKET 0 80mm THICK 3 00600 PISTONKIT D SIZE C 0 0 0 O 4 ZCMOTE11 O RINGS PIPETOFLANGE 2REQD X S O 5 ECMU0155 PISTONRINGS 2PERSET 20 6 ECMUSRO SNAP RING PISTON 2 SET 0 8 gt ECMU0077 BEARING WRIST PIN U U U O 9 ZCMUORO7 O RING EXHAUST FLANGE 0 0 V V OO Z ZKMUOR11 TOP END O RING KIT ZKCSTE11 TOP END GASKET KIT NO NIN Ci 27 Parts Exhaust System a9 PART 6 1 0032 SILENCER O 8 TCKG0001 SPACER 2 REQ D O 9 HCWF1478 SILENCER GROMMETWASHER 2REQD 625 M6X25mm FLANGE HEAD BOLT 2 REQ D _ _ __ ACCESSORY 00026 SILENCER PACKING KIT 28 Parts Forks Triple Clamps sr I T SS Et m E EE NEEDS EE ES SS END NEP EE EE ENEM TIM na L5 ZZ USA UR UNA UA SS Y TE AA A SEG S L ah waka
3. for loose nuts and bolts Turn the fuel on by rotating the fuel petcock knob to the vertically downward position reserve position is horizontally forward NOTE For best results from your Cobra Motorcycle use only the recommended fuel Testing has shown that most race fuels actually degrade performance Always wear a helmet and other protective riding gear When your pre ride inspection is complete the bike may be started For a cold engine follow this procedure 1 Place the motorcycle on a stand of sufficient strength that positions the motorcycle in a level upright position with the rear wheel off the ground 2 Pull up the choke knob and turn it to lock it 3 Kick start the engine 4 Rev the engine in short spurts turning the throttle no more than 1 4 open until the engine will run without the choke 5 Verify a functional engine shut off switch by shutting off the engine 6 Restart the engine and proceed with riding when the engine is sufficiently warm i e the side of the cylinder is warm to touch CAUTION Never rev an engine full throttle until the engine is at operating temperature This is a high performance race motorcycle Too much application of throttle will likely land your little racer on his or her arse Fenders can be replaced but bruised egos and other body parts take longer CAUTION Cobra recommends that you tell your child to take it easy the first couple of minutes in practice u
4. FORKGLIDERING e KCCS0007 FORK GLIDE RING KAMUO001 FORK LOWER COMPLETE BRAKE SIDE 31 Parts Forks Leg Assembly Non Brake Side 32 4 5 10 11 12 13 14 15 HCNJO601 33 Parts Frame Mounting Hardware Frame Engine Swingarm Tank and Pipe Mounts PART WCMUO016 HCNL 1201 880 0801 MCMUGRO2 HCBF0635 HCHAO0003 0004 0601 0006 HCBF0685 HCBB0635 HCBF0620 HCNF0602 HCBF0625 MCMUGRO03 TCKGO0001 HCWF1478 HCBF0616 FCC60020 TAMUOO005 FCMUO031 HCWF0803 008 00107 BCMU0027 HCBCO0601 DESCRIPTION SWINGARM BOLT M12 SWINGARM LOCK NUT M8X80mm SOCKET HEAD CAP SCREW M8 LOCKNUT GROMMET KIT PIPE amp SPACER M6X35mm FLANGE HEAD BOLT 6mm CLIPNUT BUSHING REAR TANK MOUNTING M6 LOCKNUT BUSHING FRONT TANK MOUNT 2 REOD M6X85mm SOCKET HEAD CAP SCREW M6X35mm BUTTON HEAD CAP SCREW M6X20mm FLANGE HEAD BOLT M6 NYLOC FLANGE NUT M6X25mm FLANGE HEAD BOLT GROMMET SILENCER 2 REOD SPACER FOR EXHAUST GROMMETS WASHER EXHAUST GROMMET M6X16mm FLANGE HEAD BOLT CHAIN ROLLER FOOTPEGS PAIR STANDARD CLEVIS PIN FOOTPEG 8mm FLAT WASHER COTTER PIN 1 8 X 3 4 FOOTPEG SPRINGS SINGLE PIECE 2 REOD BRAKE PIVOT BOLT M6X16mm SOCKET HEAD CAP SCREW FCEX0018 BRAKE ADJUST ECCENTRIC 34 Parts Frame Mounting Hardware Il Frame Seat Fender Right Side Panel Radiator 8 Shoc
5. 27 ECMUO0577 VENT HOSE CRANKCASE 3 4 5 7 10 11 12 13 14 15 16 17 18 19 20 21 22 23 23 23 23 24 25 26 27 23 Parts Engine Clutch and Kick Lever 24 Engine Clutch and Kick Starter REF PART CAMU0002 CAMU0009 CCMU0005 CAMU0014 HCBTOD0 CCMU0008 7 ECMU0018 CCMU0007 ECMU0120 ECMU0119 11 ECMU0040 CLUTCH TO HUB SPACER 0 030 0 76mm 12 ECMU0132 ECMU0306 14 ECMU0249 ECMU0305 ECMU030 ECMU0308 ECMU0307 HCCP0002 COTTER PIN 3 32 X 1 Lei NO 0 1 2 3 4 5 6 7 8 9 0 2 3 4 ACCESSORY EAMU0001 ECMU0116 ZCMUB014 HCWS1622 ECDC0036 EAMU0011 ECMU0250 HCFH0625 ECMU0115 ZCMU0030 ECMU0168P KICKSTART GEAR amp SHAFT SPRING KICKSTART O RING KICK SHAFT 2 REQ D SHIM KICK SHAFT SNAP RING KICK SHAFT KICK LEVER WASHER KICK LEVER MOUNTING M6X25mm FLANGE HEAD BOLT CLUTCH COVER GASKET CLUTCH COVER OIL FILL PLUG ALUMINUM 0608 M6X55mm SOCKET HEAD SCREW 6 REQ D ECMU0207 KICKSTART GEAR SMALL ECMUSP01 KICK START DOG SPRING PAPER CLIP J SPRING HKCP0001 10 PACK OF COTTER PINS HCCP0002 ACCESSORY EKMUO0002 KICKSTART PIVOT KIT SPRING BALL SCREW T 0022 CLUTCH SHIM HARDEWARE KIT KIT EKMU0033 CFD RFRESH KITW NUT SPRING AND FRICTIONS A gt 25 Parts Engine Water Pump Engine Water Pump DESCRIPTION 26 Parts Engine
6. REF PART j 1 KACJO001_ FORK ASSEMBLY FORK LEGS ONLY 2 0001 FORKGUARDSET 3 60019 WASHER FORK GUARD 4 REQ D 4 HCBCO601 6 16 SOCKET HEAD CAP SCREW 4 5 60015 1 1 6 0 612 M6X12mm SOCKET HEAD CAP SCREW 2 7 X HCNLOO1 MELOCKNUT 2REGD 2 8 FACJ0004 TRIPLE CLAMP BOTTOM ASSY JR CLAMP 8 STEERING STEM 9 X FCCJ205 TRIPLECLAMPTOPJR 100 0 D D 13 TKMU0404 HANDLE BAR CLAMP KIT SHORT STANDARD 14 FCMUT1103 _DUSTCOVER 2REQD oo 15 5 006 ORING 2REQD 16 FCMU0023 2 REQ D 17 FCMU0024 SEAL 2REQ D 18 FCMUO004 STEERING HEAD BEARING 2 REQ D 19 HCBCO625 M6X25mm SOCKET HEAD CAP SCREW 4 REQ D 20 616 M6X16mm FLANGED HEAD W 8mm HEX 21 HCBC0825 M8X25mm SHCS 4REQD 22 FCMU0011 STEERING HEAD RACE pg vg OO CC 00003 KIT STEERING STEM BEARINGS RACES AND SEALS HCNJO102 JAM NUT STEERING STEM 2 REOD 1 2 3 4 5 7 10 11 12 13 14 15 16 17 18 19 20 21 22 29 Parts Forks Leg Assembly Brake Side 30 6 Tkcesoos FORK OUTERTUBE32MM _ 8 Tkcos0006 FORKGLIDERINGBOTTOM3AMM 9 KCCS0032 FORKSEALSPACERGSMM Z
7. One thing to remember If your clutch is hitting fine don t mess with it Some things to remember to aid clutch Change oil each ride Gear to the low side Avoid mud if possible Cut mud practice to 1 lap or none Stay on the gas no throttle blipping Run more air pressure to allow wheels to spin helps throttle steer Make sure wheels spin freely no bent rotors dragging brakes chain too tight etc e Make sure the engines pulls cleanly and strong by having properly maintained engine with correct ignition timing and carburetion With the exceptions of component failures generally two things will occur e The clutch shoes will wear causing the clutch to engage later and e The springs will sack causing the clutch to engage earlier Typically the springs will sack at a quicker rate than the shoes will wear meaning that an un tampered clutch that worked fine will ultimately hit too early at some time When this occurs it is easily remedied with a new spring stack or a thicker flat shim Because the shoes have worn a thinner flat washer may be needed with the fresh new springs to allow proper clutch engagement 6 Effective length of the shoulder on the clutch arbor see Figure C1 Nominal is 16 00mm 0 630 As this decreases the spring stack needs to decrease equally This can change due to the shoulder bolt setting into the arbor see C2 Sink Mark Figure C1 Figure C2 If your ef
8. Geteste 88 105 12 O mn GP GP GP wues _ Statorcoverbots 17 20 23 mxo coverbots 58 70 78 wun Engine mount bols 22 25 30 mun _ Swingarm pivot 21 260 man _ Triple lamp op 12 M4 16 mus Triple clamp bottom 6 72 8 mun Water pump impeler 36 4 5 mn msxos _ intake manifold bots 46 55 62 mexo _ nition rotor mt 38 40 45 28 wies Rear sprocket bols 16 195 22 28 mxo mens 35 mo 3 was SP To apply the proper torque to the spark plug when inserting first screw ilie spark plug in until the metal gasket ring causes resistance and then turn another Ya turn Your Cobra CX50 JR is close tolerance high performance machine break in time is very important for maximum life and performance The CX50 JR can be ridden hard after the first gt hour break in time Cobra recommends Bel Ray H1 R premix oil with high octane pump gas mixed at 40 1 150 ml oil to 2 gallons of gas Other PERFORMANCE brands of oil should be mixed at 32 1 for break in LUBRICANTS CAUTION Failure to use proper fuel oil or fuel oil mixture may result in premature engine wear or damage to the machine Adhering to the following break in schedule will result in long lasting high performance machine e Start bike on stand e First 5 minute
9. is helpful to cover the sharp corners of the fork leg with tape or thin plastic before sliding on the new seal Also take care that the inner lip is not folded over when installing Slide bushing 3 onto lower fork leg Install the glide ring into groove on lower fork leg Slide the bushing over the glide ring about 1 4 to hold the glide ring in the groove Insert the lower leg assembly into the upper fork tube about 5 6 Use a seal driver to drive the seal into the upper tube Install the retaining ring Make sure it is properly seated in the groove 10 Snap the dust seal swiper into the groove in the upper tube 11 Reinstall the damper cartridge assembly to the fork leg Secure the large bolt with 22 mm wrench to 35 ft lb with green thread locking agent 12 Fill with 3 6 oz 107 ml 2 5 wt fork oil should measure 6 mm 0 25 above the damper cartridge tube with spring removed This oil volume works out to leave an oil height of 120mm from top of outer tube with forks collapsed damper rod down and spring removed 13 Install the fork spring 14 Connect the cartridge rod to the cap and tighten to 12 ft lb 16 Nm D r e o oa CAUTION The damper rod is hollow and will break if the nut is over tightened proper torgue is 12 ft lb 16 Nm Because of different rider weights sizes and riding styles we offer various suspension options See Optional Components section of this manual for details on these and other op
10. TALL 1 REQ D j ACCESSORY ALLOY BRAKE LEVER W BALL ACCESSORY BRAKE PERCH ASSY W LEVER amp BALL ACCESSORY BAKG0004 SHIELDED BRAKE HOSE ASSEMBLY 19 Parts Carburetor PILOT JET NOT SHOWN 11 12 13 14 15 16 17 20 21 25 26 27 28 29 30 31 SHOWN SHOWN SHOWN SHOWN SHOWN SHOWN SHOWN SHOWN SHOWN SHOWN SHOWN DESCRIPTION 001 OMPLETE CARBURETOR 14 RCMUO305 GUIDE 40 ELBOW SLIDE 50 MAIN JET RCMU0050 86 RCMU0086 RCMU0093 RCMU1100 RCMU0052 RCMU0087 RCMU0094 RCMU1101 65 RCMU0065 90 0090 97 RCMU0097 91 iRewuoos2 98 lt 008 20 Parts Coolant System Coolant System 10 11 12 13 14 15 16 17 PART 0004 MCMUHO02 MCMUCLO7 0001 HCBC0608 HCNLO601 MCKGGROO MCCMHOO01 TCCJ0001 FCMUO049 MCMUCLOS5 ECHAO0109 HCBCO0665 FCCJ0002 HCCNO0000 HCBCO0501 FCMU0022 21 Parts Electrical System BEES PART DESCRIPTION O Autolite B 6 HCWPO002 5mm WASHER SPECIAL 2 REQ D 8 11 00018 STATORWITHGROMMET 0 2 9 HCBC0535 M5X35mm SOCKET HEAD CAP SCREW 2 NENNEN Oj JJ FCMUO030 COVER KILL SWITCH SCREW ICMU0017 SPARK PLUG CAP 00 22 Parts Engine Bottom End and Transmission Engine Bottom End and Transmission REF PARTY DESCRIPTION EKCS
11. the pipe will decrease due to carbon build up So it is essential to clear the residue CAUTION It is important to repack the silencer Signs of your silencer needing to be repacked are e The bike is louder than normal A loss of power 62 wheel pullers Disassembly T 1 Remove axle and BE Ta back wheel UNS assembly E 2 Pull the rear wheel pullers out of the back of the swing EU arm Figure 47 Rear wheel alignment Either Accurately measure the distance from the swingarm pivot to the axle center on each side or From the rear of the bike sight up through both sprockets to ensure that the chain is running in a straight line no bend in between or jog at either sprocket Brakes Check before each ride Make sure the brake does not have any leaks by holding the lever in while checking hose connections Make sure the brake lever pressure is OK by pulling in on the lever and ensuring full braking performance is achieved before the lever touches the handlebar If this is not the case pump the lever several times until the lever feels firm Always make sure the rotor and brake pads are free from oil and grease Clean the rotor with mild dish soap or alcohol Contaminated pads must be replaced Ensure that the brake caliper is centered over the brake rotor It a correction is needed Cobra has thin brake shims to h
12. 0 05 measured at bearing journal area while supported from the ends 7 Insert case bolts with the proper lengths at the locations shown 8 Torque to 12Nm 105in Ib in the pattern shown here pU d oS T 9 away gasket material if necessary NOTE Check engine mount holes for excess material that may cause problems in engine installation 10 Install the piston with new wrist pin bearing and pin and clips CAUTION Be sure to install the piston such that the arrow on the top piston surface points to the exhaust front of bike engine and put assembly lube on the connecting rod bearing 11 Install the piston rings CAUTION Ring end gap should be no less than 0 006 0 016mm and no more than 0 020 0 5mm 12 Install the base gasket CAUTION see base gasket selection at the beginning of service section 13 Install the cylinder being sure that the piston rings are properly aligned with the indexing pins CAUTION Never force the cylinder If resistance is felt determine the problem and solve it Once installed slightly rotate the cylinder back and forth insuring that the rings are properly seated 14 Install cylinder head insert NOTE A light application of silicone grease can help hold the O rings into position during assembly 15 Install O RINGs as shown in figure 33 16 Install the cylinder head e e 17 Install the washers with flat side down
13. BCKG0013 BCMU0022 i o OJ JJ IIIJXNXJ 2 001 BRAKE PADS WITH CLIP BCKG0031 BCKG0014 BCKG0015 BCKG0016 BCKG0017 BCKG0018 BCKG0019 ZCMUORO9 39 Parts Rear Wheel BEES PART WAKG2007R WCMU1075D WCMUTU10 PCMU0001 PCMU0086 6 138 PCMUO1xx HCBHO702 HCWF0701 HCNLO701 8 WCMU0016 WCMUO101 WCMUO120 WCMU0034 WCMU0020 BCMU0502 HCBC1616 BCKG0103 BCKG0006 HCWF 1202 1201 F 0104 40 Parts Shock Rear Shock 7 10 10 10 11 ACCESSORY SCMU0058 SHOCK WHITE NYLON TIP SET SCREW 6 1 0 SCMUO056 SHOCK SLEEVE BLACK SCMU0100 BUMPER TAPPERED SHOCK SCMU0040 SHOCK SPRING PAD __ S OOOKJJJJJJU SKC60002 REBUILD KIT CARD SHOCK 41 00037 CMU0038 CMU0036 CC60007 00051 CMU0052 CMU0033 CMUO050 00035 CBB0506 00044 CMU0048 CMU0046 CMU0034 00047 CMU0045 Parts Shock Inside 9 UU 4 1 2 1 3 m Z Z lt CH Shock DESCRIPTION O RING LOW SPEED COMP ADJUSTER O RING HIGH SPEED COMP ADJUSTER O RING COMP ADJUSTER CAP O RING COMPRESSION ADJUSTER O RING IFP FP SEAL BAND RING SHOCK BASE RESERVOIR CAP RETAINER RING O RING CHARGE CAP M5 X 6mm LONG BUTTON HEAD STAINLESS STEEL EAL HEAD BUMPER HAFT BUSHING RING SEAL RING SEAL HEA
14. OQ Q NOTE When inspecting the spark plug to evaluate jetting a properly jetted machine will produce a spark plug that is dry and light tan in color NOTE Before making any carburetor jetting changes verify that o You are using the proper fuel and The fuel is fresh and uncontaminated The oil and fuel have been mixed in the proper ratio The carburetor is clean no plugged jets The air filter is properly clean and oiled The float height is within proper specification proper measuring technique is described later in this section O Sr x0 74 NOTE jetting changes motorcycle that has been warmed up to proper operating temperature 4 Clip carburetor on your Cobra Ip motorcycle is quite adjustable Straight Dia Figure 59 shows its range of adjustment and in particular what adjustable component affects what range of operation specifically throttle position PK V A Pd p Needle Taper coco Throttle Valve E Cut away Do _ Main Air Jet Main Jet Effectiveness Air sci Slow Jet IDLE 1 8 1 4 1 2 3 4 W OT Throttle Opening Figure 59 FUEL SCREW ADJUSTMENT Adjust for maximum idle speed The fuel adjustment screw is located on the left side of the carburetor It is the smaller of the two adjustment screws and requires the use of a small flat blade screwdriver for adjustment After
15. This is because an overly rich engine will just run poorly while an overly lean engine will seize potentially causing an expensive top end rebuild and a DNF To richen the carburetor 1 Change the main jet one number at a time larger 2 Lower the needle clip raising the jet needle one notch at a time until the engine starts to blubber on the top end then move the clip back up one notch or until you get the blubber out FUEL MIXTURE SCREW The smaller brass screw that is towards the front of the engine is a fuel mixture screw This screw will also richen and lean your engine more on the bottom and mid range In warmer conditions turn the screw in In colder conditions turn the screw out Be sure to keep the carburetor very clean and make sure you don t have water or dirt in the carburetor bowl Use automotive carburetor cleaner or WD 40 to clean carburetor inside and out Cleaning the carburetor WARNING CABLE MUST Clean the carburetor well ventilated area and take situatesetween care that there is no spark or flame anywhere near the screws working area this includes any appliance with a pilot light Because of the danger of highly flammable liquids do not use gasoline or low flash point solvent to clean the carburetor CHOKE KNOB 1 Make sure the fuel is shut off and remove the carburetor ELBOW 2 Remove the carburetor NE Luo 3 Drain the fuel from the carburetor 4 Disassemble th
16. adjusting for maximum idle speed use the idle screw to adjust the desired idle speed NOTE If the fuel screw requires more than 3 turns out replace the pilot jet for one that is one size richer larger number then re adjust the fuel screw IDLE ADJUSTMENT Adjust for desired idle speed The idle speed screw is located on the left side of the carburetor It is the larger of the two screws on the side of the carburetor and is unique with its knurled head for easy fingertip adjustment To raise the idle turn the screw in clockwise in 1 4 turn increments and rev the engine after each adjustment To lower the idle turn the screw counter clockwise TOP END JETTING Adjust for clean full throttle acceleration Jet your top end main jet based on the acceleration of your Cobra Motorcycle on the longest straight at the track Observe any of the lean or rich symptoms spark plug appearance and bike performance listed above and change your jetting accordingly PART THROTTLE Adjust for desired acceleration Using an area of the track that allows the rider to operate and mid throttle and transition accelerate roll from closed or mostly closed throttle to a larger throttle opening Observe the rich and lean symptoms listed above Adjust the jet needle position by moving the clip from its current position move the clip higher on the needle to make the bike run leaner or move the clip lower on the needle to make the bike run richer
17. base gasket thickness to ensure that you can always set the squish clearance of your engine to factory specifications For base gasket replacement use the code see figure 31 for location along with the table below to reorder the correct thickness gasket Base Gasket Code Stamped Here Supplied Base 6 8 Figure 31 0 6 0 024 X ZCMUO706 1081 001 ZCMUO708 NOTE Tolerances will affect the actual gasket thicknesses 45 If end parts are changed during the course of the maintenance the squish clearance should be measured and possibly a different base gasket will be required The easiest way to measure squish clearance is with 1mm to 1 5mm thick flexible solder wire available through most popular electronic stores The process 1 as follows e Assemble the top end of the engine with either 1 the crankcase stamp recommended base gasket or 2 if assembling with a new set of cases assemble with a 0 4mm 0 015 base gasket and torque the head nuts to the proper torque specifications leaving off the spark plug and ignition cover piston rings can be left off to ease of assembly e Carefully insert the solder wire though the spark plug hole into the cylinder far enough such that the tip of the wire touches the left or right side cylinder wall not the front or back as the piston will rock more and give incorrect measurement e Hold the wire at this position and rotate the crankshaft by the f
18. be achieved by testing your bike s compression with your own particular gauge after a new top end or when the bike is new so that you know what your particular gauge reads on a fresh engine When it has dropped to 90 of its original value the engine will be down on power and would benefit from a rebuild When it s dropped to 80 it really needs rebuilt Using the table below will help you determine monitor the condition of your top end Engine is Fresh Engine Down on Power Engine NEEDS Rebuilt Measured Value Measured Value 0 9 Measured Value 0 8 110 psi 110 psi 0 9 99 psi 110 psi 0 8 88 psi YouValues 0 Procedure for Compression Testing 1 Shut off the fuel petcock 2 Install the compression gauge into the spark plug hole 44 3 Hold the throttle wide open and kick repeatedly approximately 20 times or until the gauge reading does not increase in value with each kick Base Gasket Selection Tools reguired e 1 mm wrench e 1mm flexible solder material e measurement calipers When rebuilding the top end of your Cobra motorcycle care must be taken to ensure the proper squish clearance Squish clearance 1 defined as the minimum distance between cylinder head and piston at There are negative effects of either having too much or too little clearance Since parts like the crank connecting rod cylinder head piston and crankcases all have varying tolerances Cobra offers several different
19. carburetor jetting 8 Reinstall the filter boot assembly making sure the letters CM are visible between the carburetor and air box figure 4 NOTE Make sure you change or clean your filter after each moto We recommend carrying multiple filters in your toolbox one for each practice session and moto 14 Maintenance Cobra strongly recommends that a professional service technician conduct all internal maintenance other than changing springs and oil This will help to ensure safe and consistent operation For routine maintenance the chart below provides suggested service intervals for common procedures e Each Ride 20hours Ae Needed Needed ru Seal Swiper er Change Bushings X Air Bleeding Tools reguired 3mm hex key Allen wrench During normal operation both fork legs will build up air pressure This pressure acts as an additional spring so it must be bled on a regular basis to maintain consistent suspension operation Before each ride loosen the socket head cap screw located at the front of each fork cap far enough so that any excess pressure in the leg is relieved After excess air is bled off retighten the screw to 5 in Ib Be careful not to lose or damage the sealing ring that is located under the head of each bleed screw Fork Oil Replacement Tools reguired 32mm Fork Tool MCMUTL32 PERFORMANCE 19mm wrench or socket
20. for the engine coolant and disconnect the coolant lines connected to the engine 8 mm socket DO NOTE If the coolant looks to be free of contaminates it may be reused 7 Remove the master link from the chain 8 Remove front engine mount bolt 13 mm socket 6 mm hex key 9 Remove the swingarm bolt 19mm socket NOTE Only drive the swingarm bolt far enough to clear the engine leave it holding the one side of the swingarm to the frame 10 Remove the engine from the right side of the frame Complete Engine Disassembly Procedure 1 Remove the ignition cover 4mm Allen 2 Remove the bolt from the water pump shaft 4mm Allen and slide off the belt cover and the water pump belt 3 Using a flywheel holding tool and 14mm socket remove the nut that secures the flywheel 4 Using the Cobra flywheel clutch puller ZMCMUTL70 remove the flywheel from the crankshaft 5 Remove the stator 4mm Allen 6 Remove the left hand thread nut holding CFD to transmission input shaft using the CFD gear stop 004 and a 19mm socket 7 Remove the clutch nut starter gear that holds on clutch using clutch nut removal tool 078 8 With the Cobra flywheel clutch puller K 6gMgMCMUTL70 remove the clutch from the crankshaft details in Clutch Service portion of this manual Top End Disassembly Procedure 1 Remove the cylinder head nuts 10mm 2 Remove the cylinder head outer 3 Remove t
21. nuts Torque to 123 in Ib 14 Nm Figure 33 18 Install reed and intake manifold with new gasket Torque to 55 in Ib 6 2 CAUTION The intake manifold bolts will require being checked and torque values reset after a few heat cycles 19 Leak check the engine at 20 psi to ensure proper seal 20 Install stator reinstalling the grommet and wires 21 Install the rotor per Rotor Installation section under the S3 50 Ignition portion of this manual 22 install the water pump outlet pipe apply Hi Temp RTV silicon gasket maker to the threads before assembly before installing the clutch and rotate to a vertical position with the engine resting on bench 23 Install the CFD 24 install the clutch per Clutch Installation section in this manual 25 Install the coolant drain plug with copper washer 11 ft lb 15 Nm 26 Make sure that the exhaust spacer is on the cylinder 53 in Ib 6 Nm 2 nstall the spark plug with a fresh gasket to apply the proper torque to the spark plug when inserting one must first screw the spark plug in until the metal gasket ring causes resistance and then turn another 1 8 to turn Clutch New for 2014 Cobra has again improved the clutch design The new washer stacks are similar but of a different more heat resistant material the shoulder bolts have been replaced with a patent pending sleeve bolt assembly and the shoes and basket have been modified to improve the oil flow though The s
22. that set is easily accessible PRELOAD HEH Shock Damping MECHANICAL PRELOADING ADJUSTMENT Q 14mm NUT HIGH ADJUSTMENT 4mm HEX REBOUND DAMPING LOW SPEED ADJUSTMENT ADJUSTMENT RING Sep d MORE DAMPING LESS DAMPING L MORE DAMPING lt N LESS DAMPING 11 Adjustment of rebound damping 12 Adjustment of compression damping Carburetion Although your Cobra is sent from the factory with the carburetor jetted for optimal performance you may find it necessary to adjustment your particular jetting due to current weather conditions altitude fuel variations and or engine modifications 73 CAUTION Proper jetting is very important for engine performance and engine life Symptoms of improper jetting are listed below Symptoms of incorrect oil or oil fuel ratio o Poor acceleration Misfire at low engine speeds Excessive smoke Spark plug fouling Excessive black oil dripping from exhaust system e Symptoms of too rich a fuel mixture Poor acceleration Engine will not out blubbers on top Misfire at low engine speeds Excessive smoke Spark plug fouling Wet black or overly dark spark plug when removed for inspection e Symptoms of too lean a fuel mixture o Pinging or rattling Erratic acceleration Same actions as running out of fuel High engine temperature White spark plug when removed for inspection O O O O Er
23. the frame for cracks in the metal or cracks in the paint that might Indicate that the metal has been stressed beyond its safe limits o Check the rims for signs of stress like cracks around the rim spokes and hub o Equalize the pressure in the forks with atmosphere Every 2 hours of operation o Replace the transmission oil o Check the CFD torque Every 10 hours of operation o Replace the fork oil o Have the shock oil replaced by a Certified Cobra Mechanic Ov EE O Replacing Transmission Clutch Lubricant Tools needed e 5mm allen wrench Minimum of 235 ml 8 oz Cobra Venom 3 Shoe Clutch Milk ZMCMUGF32 Procedure 1 Begin this procedure with a bike that has been ridden more than 5 minutes but less than 10 minutes It is desired to have the engine warm enough so that the oil is runny but not so hot that there is risk of being burned by the engine or the oil Hot oil and hot components on the motorcycle may cause burns 2 Remove the oil drain plug on the clutch cover near the brake lever figure 1 P7 lt O d Oil Fill Figure 1 3 Allow the oil to completely then reinstall the oil plug 4 Remove the fill plug and add 8 002 of Cobra Venom 3 Shoe Clutch Milk thru the oil fill plug NOTE Putting additional oil up to 350 ml 12 oz can help clutch life More than 390 ml 12 oz will degrade engine performance NOTE can be helpful to lean the bi
24. 0 11 12 Sc The frame is 4130 Chrome Moly and it is important to weld it with the proper rod and heat settings set as light as possible Cobra recommends replacing the frame with a new one if the old one becomes damaged Use ER70S6 filler if welding on the frame lf your kick starter lever does not return properly first try loosening the six kick clutch cover screws 72 turn Hold the kick lever 72 way down while retightening the six screws starting for the center and working out Inspect CFD slip torque after the 27 ride and then again after the 6 ride After this follow the recommended schedule below Check proper clutch engagement before and after each ride If the clutch is engaging properly DO NOT feel the need to take the clutch apart to measure the spring stack clean the stack replace the springs etc Cobra has worked very hard to make a clutch that is low maintenance and so only take it apart if it NEEDS to be maintained hedule Prior to each ride o Check that the air filter is cleaned and oiled Insure the smooth operation of the throttle cable throttle soundly clacks shut Check for frayed strands of the throttle cable inside the throttle housing Check for adequate tire pressure Check all nuts and bolts for proper torque Spray all moving parts with WD40 or other light oil Check drive chain for Proper tension m Adequate lubrication Insure that the ignition stator and rotor are clean and dry o Check
25. 0003 ENGINE CASE SET WITH BEARINGS amp SEALS ZCCS0005 GASKET CRANKCASE CENTER HCBCO0605 M6X40mm SOCKET HEAD CAP SCREW 6 REQ D 9 _ pou 5 0608 6 55 SOCKETHEADCAPSCREW TREQD 6 lt 0606 6 45 SOCKET HEAD CAP SCREW 2 REQ D 7 ECMU0057 CRANKSHAFT 3 SIDE SPLINE 0 2 8 ECMU0016 BEARING CRANKSHAFT 00 9 ECMU0118 SEAL CRANKSHAFT 0 00 10 HCDP1401 DOWEL ENGINE CASE ALIGNEMENT 2 REQ D 2 11 DECMU0999 OUTPUT SHAFT TRANSMISSION WITH GEAR 12 0100 SECONDARY SHAFT TRANSMISSION WITHGEAR 13 ECMU0001 BEARING TRANMISSION SECONDARY SHAFT 14 ECKG0031 BEARING OUTPUT SHAFT RIGHT SIDE 15 0612 M6X12mm HEX HEAD SCREW BEARING RETAINER 2 16 HCWFO316 WASHER FLAT 17 ECMU0020L_ BEARING TRANSMISSION PRECISION 18 ECKGBRO1 BEARING TRANSMISSION OUTPUT SHAFT 19 ZCDCORO O RING SPROCKET SPACER oO o ooo 20 ECMU0072 SEAL OUTPUT 0 21 ECMU0073 SPACER SPROCKET 22 ECKGSRO3 SNAP RING SPROCKET 22 PCKG0013 SPROCKET 13T STANDARD ZU o Z o 22 PCKG0012 SPROCKET 127 23 PCKG0014 SPROCKET AT 0 23 PCKG0015 SPROCKET 15 24 HCBH0805 M8X12mm SCREW COOLANT DRAIN 0 0 25 0000 COPPERGASKET 0 4 o 20 ECMUO0233 FITTING CRANKCASE VENT LARGE
26. 6 0 16 mm and 0 020 0 5 oplitting the Cases 1 Remove the fasteners holding the two halves of the crankcase together 2 Separate the cases with a proper case splitting tool CAUTION Take caution when handling the crankshaft It is the main power transfer to the rest of the engine If it is out of alignment it will cause premature failure of your bearings which can lead to serious damage to the cylinder as well as the rest of the engine Do not try to true the crank yourself Truing the crank should be done professionally CAUTION e f you split the cases check the gear tooth faces for chipping amp signs of fatigue e Check the small needle bearings for fatigue the bearings are damaged the engine cases should be checked to make sure the needle bearing casing didn t oblong the bearing hole in the case Needle bearings should be replaced every 2 months Engine Assembly CAUTION For any seals that are to be installed apply a light amount of grease to the seals ID assembly lube on all bearings and a small amount of Loctite to the OD Press the three bearings into the respective holes in each case half Press in the crank seals such that the concave side faces the crank weights Press in the counter shaft seal concave side faces inside of transmission Press in the water pump assembly Tap both ways axially then verify easy rotation Inspect the crankshaft for proper true geometry no more than 0 002
27. 6 17 18 19 20 22 23 24 26 43 Service Trained technicians with precision gauging and proper assembly fixtures carefully assemble all Cobra engines to specific tolerances If you feel you have the skills and the appropriate tools to perform the following service tasks please follow the instructions closely The part numbers are listed throughout to help you when ordering parts from your local Cobra dealer If you do not feel comfortable with the service work log to www cobramotorcycle com to find a cobra dealer or call 517 437 9100 Engine Service One method for determining whether the top end of your engine needs rebuilt 15 to perform a wide open throttle kicking compression test Before performing the procedure please read the caution notes below CAUTION e There is a large wide range of variability in reading compression gauges e head volume of this Cobra Motorcycle is very small and requires 20 kicks before you establish the most accurate reading possible e Because of the geometry of the spark plug used in this Cobra Motorcycle the adapter used with your compression tester must have a similar volume protruding into the combustion chamber to establish an accurate value e Length of hose on the compression tester will affect the reading The shorter the hose length the more accurate your reading will be Because of these difficulties in measuring an absolute compression value a useful relative value can
28. 9 ENGINE ASSEM NOM oe 49 51 2f elec NR O 55 BE 56 COOR RE EE 57 Radiator Id Me ue EE 57 PUCK ec AI SY StS uy 60 Te 60 Ricco cc 62 F QU S Suyu mua 62 near wheel Em 63 ETE 63 PSA INO ged Cm 65 m mn S yma undo Dan uos 66 OE NIC 70 PAIS UNG EE 70 71 Fork Dariping d Va 71 EE un E 72 Ee e 73 Troubleshooting 76 Ile E 78 General Information Specifications General Mem 2 0 Dimensions Wheelbase Wheel size Seat height Engine Type Cooling system Coolant Displacement Bore and stroke Ignition system Spark plug Gap Ignition timing Fuel type Premix Oil type Premix oil ratio after break in Carburetion Slow Pilot Jet Main Jet Float Height Transmission Speed Clutch Final d
29. A NOTE provides key information to make procedures easier or clearer MCCJ2015 0 Table of Contents General Norma O In DEE 4 EE e LE DI 4 Optional SUSPENSION gt ec 5 Specifications Kee HEITE 5 Br ak Irn Procedure dde ere pae 6 EN 7 VE TEE 8 Blat 8 EE 9 Replacing Transmission Clutch Lubricant 10 Proper Chain Le E Ed nda 11 Rear Brake Maintenance ana 11 Brake Bleeding Procedure 13 Filter guabas aus 14 Fork Maintenance a a db d d Rua a e NO 15 m 15 FOK OIRO DLA CCI E SERT 15 Cobra Frictional Drive Vo 16 PANES uu u 18 Parts Airbox and Inlet System i ete auae aeuo eene dte gua aue Rena 18 Parts bars and CONTOS asset ir decer iter Doi d dE ta ri a adi UE 19 Pans CA uuu u uuu N 20 EE 21 Parts e der EE ER Parts Engine Bottom End and Transmission
30. D PACER X RING DUST SEAL SCC60014 PISTON BAND SKC60002 REBUILD KIT CARD SHOCK 42 Parts Swingarm Assembly 19 PART v 1 GACJ2011 SWINGARM ooo 22222 GCMU0001 SWINGARM BUSHING SINGLE PIECE 4 REQ D 3 0001 SPACER PIVOT TUBE 2REQ D 2220 4 000177 CHAIN GUARD gt 5 0512 M5X12mmFLATHEADSCREW _ 6 501 5mm FLATWASHER 222 7 MSLOCKNUT 8 HCBF0620 M6X20mm FLANGE HEAD BOLT 2 9 001 CHAIN GUIDE ASSEMBLY COMPLETE 10 0004 CHAIN GUIDE BOTTOMSLIDER 0 211 HCBFT640 M6X40mm FLAT HEAD BOLT 2 220 12 0601 M6 LOCKNUT 2 REQ D 025004444442 123 FAMUOO005 WHEEL PULL ASSEMBLY BLOCK CAP BOLT AND WASHER 14 FCMU0203 WHEEL PULL gt 15 FCMU0202 WHEEL PULL ENDCAP 0 0 16 HCWF0801 8mm FLAT WASHER 22 o HCWLO801 8mm LOCK WASHER 00509459022 17 0810 M8X65mm HEAD BOLT FULL THREAD 18 WCMU0016 SWINGARM PIVOT BOLT 195mm 00 19 HCNL1201 M2LOCKNUT 20 WCMU0016 AXLE BOLT 5mm S 22 HCWF1202 AXLEWASHER 1 1 O 23 HCNS120 M12LOCKNUT 24 HCBF1040 M10X40mm FLANGE HEAD BRAKE HOSE CLAMP 2 for hose with clear cover 26 0832 BRAKE HOSE CLAMP FASTENER 2 2 2 1 2 3 4 5 7 10 11 12 13 14 15 1
31. DISCLAIMER WARRANTY This motorcycle is sold as is with all faults obvious not There are no warranties expressed or implied including any warranty of merchantability and warranty of fitness for any particular purpose WARNING THE COBRA CX50JR IS A COMPETITION MODEL ONLY AND IS MANUFACTURED FOR NOR SHOULD IT BE USED ON PUBLIC STREETS ROADS OR HIGHWAYS THE USE OF THIS BIKE SHOULD BE LIMITED TO PARTICIPATION SANCTIONED COMPETITION EVENTS UPON A CLOSED COURSE BY A SUFFICIENTLY SKILLED RIDER AND SHOULD NOT BE USED FOR GENERAL OFF ROAD RECREATIONAL RIDING IMPROPER USE OF THIS MOTORCYCLE CAN CAUSE INJURY OR DEATH THIS BIKE IS INTENDED FOR EXPERIENCED RACERS ONLY AND NOT FOR BEGINNERS IT IS YOUR RESPONSIBILITY AS THE OWNER OF THIS COBRA MOTORCYCLE OR AS THE PARENT OR LEGAL GUARDIAN OF THE OPERATOR TO KEEP THIS COBRA MOTORCYCLE IN PROPER OPERATING CONDITION THIS BIKE WAS DESIGNED FOR RIDERS THAT WEIGH LESS THAN 80 LBS WITH FULL RIDING GEAR AND SHOULD NOT BE OPERATED BY RIDERS THAT WEIGH MORE BE SURE THAT THE RIDER ALWAYS WEARS ADEQUATE SAFETY GEAR EVERYTIME HE OR SHE RIDES THEIR COBRA MOTORCYCLE IMPORTANT SAFETY NOTICE Failure to follow WARNING instructions could result in severe injury or death to the machine operator a bystander or a person inspecting or repairing the machine CAUTION A CAUTION indicates special precautions that must be taken to avoid damage to the machine NOTE
32. Jetting too lean e Too much throttle blipping f Too high gearing g Kinked radiator hose h Rear brake dragging Chain too tight j Air leak Engine won t idle a Idle knob needs adjusted b Air leak C Carburetor jets are dirty Tf Air Filter Maintenance 14 Airbox PAL IS 18 Bars and Controls 19 Base Gasket Selection 45 cede iet eu tinte ott 6 Carburetor Hate 2 0 ec un usus usus sussusqa 20 SEVICE 60 OPECINIGAUONS 4 TUNDO muu masa 73 CFD Cobra Frictional Drive 16 Chain NEIES adis dera deutet deabus 11 Chassis Specification 4 Clutch NLS RE 24 Clutch Lubricant 10 Compression test 44 Cooling System 57 Engine 4 Exhaust 62 28 Fork Adjustments 71 71 Fork 15 16 Frame Parts Frictional Drive Front Brake Front Wheel Parts Fuel System Service Hardware and Fasteners Troubleshooting Lubrication Recommended Maintenance Schedule Recommended Optional Components Parts Airbox and Filter Bars and Controls Bottom End amp Transm
33. LUBRICANTS 4 amp 5 mm hex key Allen wrench e 9 16 wrench e Mallet e 2 5 wt Bel Ray fork oil 15 Disassembly procedure Remove the front wheel 19 mm wrench Remove the brake caliper from the fork leg 4 mm key Loosen the fork caps 32mm fork cap tool Remove the fork legs from the triple clamps 5 mm hex key One leg at a time a Remove the fork cap from the fork tube b Pull the fork spring down to gain access to the fork cap jam nut and secure it with a 9 16 wrench Holding in one hand the 9 16 wrench use the fork cap wrench to unscrew the fork cap from the damper rod d Remove the fork spring pad and fork spring e Inside the damper rod the rebound adjustment screw pin is resting and will fall out of the damper rod when the fork is inverted Try to catch it before it falls into your oil bucket f Invert the fork and allow the oil to drain completely Working the damper rod up and down will speed up the draining process oh A Assembly procedure Fill the fork with 140ml of fork oil Work the damper rod up and down to allow the fork cartridge to fill with oil Install the rebound adjustment screw pin into the damper rod Install the fork spring and spring pad Extend the damper rod completely and Compress the fork spring enough to begin threading the fork cap back onto the damper rod Make sure that the fork cap threads onto the damper rod completely before it makes contact with the jamn
34. UD HOLD 5C SPACER FRONT TANK MOUNT 2 REOD 5D 6 85 SHCS FRONT TANK MOUNT 5E M6 LOCK NUT FRONT TANK MOUNT BOLT 5F M6X45mm SOCKET HEAD CAP SCREW 5G BUSHING REAR TANK MOUNTING CAP FUEL TANK HOSE FUEL CAP FUEL PETCOCK SEAT 9A SEAT COVER REPLACEMENT M6X40mm SHCS SEAT HOLDING 9C STRAP HANDLE 10 amp 11 NUMBER PLATE SET LEFT AND RIGHT WHITE 10 amp 11 NUMBER PLATE SET DENOTES COLOR BLK WHT YEL 10A M6X16mm FLANGE HEAD BOLT FRONT SECURE 10B M6X20mm FLANGE HEAD BOLT FENDER amp REAR SECURE 10C M6 NYLOC FLANGE NUT 10D M6X16mm FLANGE HEAD BOLT FRONT SECURE 10E M6X20mm FLANGE HEAD BOLT FENDER amp REAR SECURE 10F M6 NYLOC FLANGE NUT 12 FENDER REAR FLO YELLOW 12 FENDER REAR x DENOTES COLOR BLK WHT YEL FLO 12A M6X16mm FLANGE HEAD BOLT FENDER amp AIRBOX ACCESSORY GRAPHIC KIT ACCESSORY BODYWORK KIT JR BLACK ACCESSORY BODYWORK KIT JR WHITE ACCESSORY BODYWORK KIT JR YELLOW ACCESSORY TKCJO002FLO BODYWORK KIT JR FLO YELLOW 38 Parts Rear Brake PART 002 BCMU0027 BCMUOS01 1 2 3 A REF NEN EN 2 BCMU0029A BCMU0023T HCBCO501 BCMUSP02 6 0601 0018 8 1 0003 9 X 006 10 BCKGO103 NENNEN 10 11 12 HCBF0620 HCCC0000 HCCC0006 HCPP0832 BCMU0502 HCBCO601 HCBF0620 0012 2 HCBF0635 M6X35mm FLANGE HEAD BOLT BCKG0010
35. ch nut and torque to 40 ft lb 54Nm INSPECTION NOTE There must be in out play in installed clutch 0 3mm to 1 0 mm 0 012 to 0 0407 This should be adjusted with the ECMUOO40T and ECMU0040 shims A blue clutch drum is worn out from excessive slippage improper lubrication 7 Install the clutch cover tightening the bolts from inside out 8 or 10 mm socket 5 8 ft lb 7 8 Nm NOTE To ensure proper engagement of the kick gear with the starter nut tighten the six screws only to the point of being not extremely loose Using one hand rotate the kick lever to 72 stroke and hold while tightening the six screws completely with the other hand 8 Fill with oil 295 ml 10 0 oz Cobra 3 Shoe Clutch Milk Part MCMUGF32 99 Ignition Stator care Stator failure could result from running the bike hot Following is a list of things that will make your engine run hot 1 The timing should not exceed the maximum specifications listed 2 Improper carburetor jetting 3 Improper spark plug heat range Never run a hotter plug than the specified spark plug 4 Clutch slippage See CLUTCH section for causes of slippage CAUTION e Because of the amount of heat generated by the clutch and engine during extended periods of riding it is advisable to remove the ignition cover afterward to allow the ignition to cool off The heat transfers through the cases and can damage the stator as it cools off because of lack of a
36. clutch on your motorcycle is performing the best possible from the shop and so it may have a different clutch stack or shim washer from what you are used to Please take measurements for knowledge sake but don t blindly restack washers to different heights without first consulting the factory 68 Gearing For a bike with a centrifugal clutch it s better to be geared too low than too What happens with improper sad o Vo gearing e performance snap Premature failure of engine seals bearings amp electronics High cluteh wear It may be helpful to set up the clutch to hit early for smooth power delivery Suspension Adjustment 1 Front forks 1 1 Fork oil 1 1 1 Oil type 1 1 1 1 Heavier weight oil more damping slower responding 1 1 1 2 Lighter weight oil less damping quicker responding 1 1 2 Oil quantity level 1 1 2 1 Greater quantity higher level greater bottoming resistance stiffer near the end of the travel 1 1 2 2 Smaller quantity lower level less bottoming resistance less stiff near the end of the travel 1 2 Fork spring 1 2 1 Stiffer spring higher spring rate stiffer throughout the travel 1 2 2 Less stiff spring lower spring rate less stiff throughout the travel 3 Gas pressure always bleed off any pressure 4 Fork height 1 4 1 Rise in clamps for quicker turning 1 4 2 Lower in clamps for improved st
37. e carburetor 5 Immerse all the metal parts in a carburetor cleaning Figure 45 Proper carburetor top solution installation And location of rectangular After the parts are cleaned dry them with indexing and vent elbows compressed air 61 7 Blow out the fuel passages with compressed air 8 Assemble the carburetor 9 Install the carburetor onto the motorcycle CAUTION The motorcycle will only operate properly if the carburetor top is installed properly with the mounting screws cable and choke knob oriented as shown in figure 45 Reeds The reeds must lay flat on the reed cage If the reed tips aren t lying flat replace them immediately The reeds must have a tight seal on the reed cage If the reed is damaged in any way replace it This means cracks chips and ruptures Anything abnormal replace the reeds Take the reed cage out and hold it up to the light and look in through the cage If you see light between the reed pedals and the frame then replace the reeds If you do not see light then the reeds should be ok Exhaust The pipe is a crucial element to a motorcycle Any kinks dents or damage done to the pipe will result in a major performance loss NOTE Be sure to take the pipe off and any carbon that may be built up Carbon build up is created from exhaust Exhaust has oils in it and the oils cling to the walls of the inside of the pipe Over a long period of time the diameter of
38. ed with an adjustable carburetor Some fine tuning may be needed according to weather condition and altitude Proper jetting is very important for engine performance and engine life Serious damage to the engine can occur if not properly adjusted IDLE ADJUSTMENT On the left side of the carburetor there are two adjustment screws The larger screw with the knurled head is the idle adjustment screw To raise the idle turn the screw in clockwise in 1 4 turn increments and rev the engine after each adjustment To lower the idle turn the screw counter clockwise TOP END JETTING Indications that the engine is running too rich too much fuel for the air are e Engine not revving out or blubbering at high RPMs e Engine will not clean out e Wet or black spark plug NOTE Before changing jetting be sure that the air filter is properly cleaned and has the usual amount of air filter oil An overly dirty air filter can cause the engine to run rich 60 If the engine is running rich on top end it should be leaned out Leaning it out can be done by 1 Changing the main jet to a smaller number 2 Raising the needle clip this lowers the jet needle one notch at a time on the slide Indications that the engine is running too lean are e Engine cutting out on top end Engine overheating and ultimately seizure e White spark plug CAUTION It is much safer to operate the engine slightly rich as opposed to slightly lean
39. elp make minor adjustments in alignment Always leave adequate free play in the lever or pedal CAUTION This brake system uses only DOT 4 or 5 1 brake fluid 63 Front Forks Tools recommended for front fork service Flat head screwdriver Hammer Pick Seal driver MCMUTLO2 9 16 loose 14 mm wrench 25mm wrench or socket 2 5 wt fork oil FORK DISASSEMBLY PROCEDURES 30r E O OO Using the 25mm wrench remove the fork cap Drain the fork oil into a suitable container Disconnect the fork cap from the damper rod 9 16 wrench 8 25mm wrench Disconnect the damper assembly from the fork leg by removing the large aluminum bolt from the bottom of the fork leg 22mm wrench Pry the dust seal swiper from its position with a small screw driver Using a pick remove the wire retaining ring holding the fork seals into place Pop the fork seal out by forcibly pulling on both ends of the fork tube assembly thus separating the inner from the outer tube Remove the bushings Clean all components to be reused FORK ASSEMBLY PROCEDURES Figure 46 CAUTION Make sure all components are clean before assembly CAUTION Be sure to apply oil to the new fork seal and other components before installing T 2 3 Slide dust seal swiper 6 onto lower fork leg Slide retaining ring 5 onto lower fork leg CAREFULLY slide seal 4 onto lower fork leg with spring facing away from snap ring 64 CAUTION
40. ely up against the sprocket 4 Verify with a torque wrench applied to the Sprocket socket that the V3 CFD does not slip below 81 Nm 60 ft lb in either direction 5 If there is slippage below 81 Nm 60 ft lb remove the cotter pin and tighten the nut on the CFD one more position it is a hand thread nut so you must turn it counter clockwise CAUTION Do not check earlier versions of the CFD with this method The torque valves required at the sprocket would be much higher HINT This V3 CFD torque checking method is possible do to with the chain on Just put the bike on a stand so that the rear wheel can turn freely HINT The CFD hubs can be removed with the universal puller MCMUTL 70 17 Parts Parts Airbox and Inlet System Airbox and Inlet System DESCRIPTION GASKET REED TO CYLINDER REED CAGE ASSEMBLY WITH REEDS VFORCE INLET MANIFOLD 6mm FLAT WASHER REF 6 4 HOSECLAMP CARBURETORTOMANIFOLD 8 RCCM1301 VELOCITY STACK 9 MCKGHOO1 HOSE CLAMP AIR BOOT TO CARBURETOR FUEL LINE 5 NOT SHOWN 18 Parts Bars Controls Bars and Controls DESCRIPTION HANDLEBAR ALUMINUM GRIPS SET OF TWO SCOTT WAFFLE THROTTLE ASSEMBLY CABLE COVER THROTTLE COVER THROTTLE CABLE BRAKE ASSEMBLY FRONT KILL SWITCH ASSEMBLY M8X30mm SOCKET HEAD CAP SCREW 4 REQ D 10 M8X25mm SOCKET HEAD CAP SCREW 4 REQ D 11 BAR MOUNT KIT SHORT 1 REQ D STANDARD 11A BAR MOUNT KIT
41. emoved from the system Remove the syringe Be sure to keep the caliper below the level of the reservoir to allow the fluid to run out of the caliper and not allowing air into the system Reinstall the bleed screw being sure that the ring is in place Fill the reservoir with fluid the fluid should be full enough that the fluid spills out when placing the lid on and replace the cover 13 Air Filter Cleaning Tools recommended for air filter maintenance e 2 Phillips head screwdriver e 4mm Allen wrench e Foam filter oil Procedure 1 Removed the seat with a 4 mm Allen wrench 2 Remove the filter air inlet boot from the back of the carburetor with a Phillips screwdriver 3 Pull the filter boot assembly out the top of the air box 4 Clean the filter in a nonflammable solvent to remove the filter oil Do not clean the air filter with gasoline or other highly volatile petroleum product Diesel fuel or kerosene would be preferred but caution should still be taken Hot soapy water works well 5 Clean the filter in hot soapy water to remove all dirt particles 6 Allow it to dry thoroughly 7 Saturate with filter oil and remove excess NOTE The Cobra is equipped with a special designed Air box It is very important to keep the air filter clean and properly oiled with high quality water resistant foam filter oil very important to oil your filter consistently each time because varied amounts of oil will change your
42. fective shoulder length is off or your shoes are worn adjust the height of your overall combined spring stack accordingly i e if your effective shoulder length is 0 5mm short of the 16 00 measurement decrease the overall combined spring stack height by 0 5mm or if your shoes are worn by 0 5 mm increase the overall combined spring stack height by 0 5mm Frequently asked questions Q When should the springs be replaced A When the clutch hit occurs too early or too late Q Should the clutch springs be replaced if the shoes wiggle on the arbor A Not if the clutch is hitting correctly Don t mess with it Q What is the acceptable tolerance on any of the measurements A For the most part that does not matter Suffice it to say that any efforts to make the three shoes behave identically will make the best performing clutch Taking extra time to balance the three stacks shims springs bolts etc to as close to the same length as you are willing to put effort into will result in a better performing motorcycle Q One of my two riders weighs 85 pounds and the other weighs 45 pounds Should have their clutches adjusted differently because of their weight A No there is one best setting and it works for light or heavy riders O If my clutch basket changes color should replace it A If itis blue or purple replace it If it is silver or brown you are fine Cobra is now going to greater lengths to ensure that the
43. gine coolant as described above NOTE If the impeller is damaged or broken completely back flush the coolant system to ensure no solid pieces are in the system 2 Remove ignition cover using a 4mm hex key four places 3 Stick a 3mm hex key in the water pump shaft cross hole and remove belt retainer screw using a 4mm hex key Figure 42 item 1 4 Remove belt retainer water pump belt and water pump fan pulley 5 Remove bearing retainer screw using a 3mm hex key 6 Thread a slide hammer onto the end of the water pump shaft and remove the assembly NOTE It is quite common for the older plastic impellers to fall off the end of the shaft during this step of the process if that is the case then follow the steps at the end of this section to remove the seal and impeller 58 7 Clean any debris particles from bore and use some light emery cloth to remove any scratches in the surface that the removal process may have created 8 Lubricate the bore with grease 9 Prepare for assembly by installing the water pump assembly into the assembly tool and align the tool with engine case making sure alignment pin is in proper hole CAUTION Damage may occur if one attempts to install the water pump and the device is not orientated correctly If the tool does not sit flat against the cases the orientation of the tool to the engine is not correct Make sure that the top alignment pin is in the 274 unthreaded hole t
44. he bottom alignment pin is also in the 27 unthreaded hole and that the relief for the stator bolt head is oriented toward the stator 10 Hold the installation tool firmly against the engine case and tap on the end of the water pump shaft with a dead blow hammer until the insertion punch is needed 11 Continue driving the assembly with the punch until the head 1 flush NOTE The insertion punch is 0 010 0 25 longer than the housing so as to seat the water pump assembly just in from the case surface 59 12 assembly is installed when retaining can be tightened and it does not cause a bind on the spinning shaft use medium strength thread lock retainer screw NOTE be necessary to tap the water pump shaft in hammer and out with slide hammer to insure proper free operation of the shaft 13 Reinstall the pulley belt and fan cover using a 3mm hex key to stop the rotation of the water pump assembly while tightening with medium strength thread lock to 10 ft lb 14Nm 14 Reinstall the cover NOTE Refill the coolant system with 50 50 antifreeze coolant distilled water CAUTION Do not mix Propylene Glycol based coolant antifreeze solutions with Ethylene Glycol based coolant antifreeze solutions Fuel amp Air System Carburetor Tools recommended for carburetor service Small flat head screwdriver e WD 40 Omm socket Your Cobra is equipp
45. he cylinder head insert INSPECTION NOTE Inspect the cylinder head for deposits and abrasions 1 If there are deposits they should be removed a Black oily deposits indicating a rich mixture or improper oil type quantity can be removed with solvent b Crusty deposits indicating dirt ingestion can be removed with solvent and may require some scraping 2 Abrasions a Pitting or erosion indicates detonation and may require cylinder head replacement also i Retard the ignition timing li Use a higher octane fuel b Missing chunks or indentations indicate broken hardware or ingested items replace the cylinder head 4 Remove the cylinder INSPECTION NOTE Inspect the cylinder bore for abrasions deposits and missing coating 1 If abrasions scrapes scratches pitting etc are found replace the cylinder 2 If deposits all are found a Clean with muriatic acid b Once the deposits are removed inspect for abrasions and missing surface coating i If there are abrasions or missing coating replace ii If all looks well the cylinder may be saved Muriatic acid can be dangerous Follow the manufacturer s instructions closely 5 Remove the piston clip with a scribe 6 Remove the piston pin with a piston pin remover 48 INSPECTION NOTE Inspect the piston for abrasions and deposits on the top and sides and clean or replace as necessary INSPECTION NOTE Piston ring end gap should be between 0 00
46. hen traversing sharp GOTTOM T edged bumps Bike tends to jump rear end low Softer rebound damping Freguent rear end bottoming Harder compression damping Bottoms after end of continuous bumps Softer rebound damping 1 Harder rebound 2 Softer Compression Rear end kicks over sguare edge bumps Rear Shock Adjustments Always start with standard settings and make damping changes in no more than two click increments and only make one change at a time Symptom 0 Damping Damping Rear end kicks over sguare edge bumps 1 Harder rebound 2 Softer Low and High Speed Compression Rear end feels stiff under acceleration Softer Rebound and or Stiffer Low bumps Speed Compression Damping Proactive Suspension Adjustments 72 Once you have suspension adjusted for decent feel you make proactive adjustments when faced with different racing conditions Situation 7 02 Sand track Lower the rear end increase race sag Sand track Stiffer compression and rebound damping Long fast track Lower the forks in the clamps by 3 mm Tight slow track Raise the forks in the clamps by 3 mm Mud track Lower the bike if the rider has difficulties touching the ground Shock preload Loosen the set screw and turn the spring perch in PRELOAD full turn increments to get the desired sag settings HEIGHT NOTE Always leave the spring perch rotated such position so
47. ing your clutch springs Clutch basket wear e he internal diameter of a new clutch basket should measure 84 10mm Over time the clutch shoes will wear the internal surface down creating a bigger ID and causing a later engagement The maximum ID we recommend to allow is 84 25mm 54 CAUTION The clutch produces a tremendous amount of heat and when a rider is blipping the throttle This makes the clutch and clutch springs wear out quicker This also makes your engine tend to run hotter which decreases engine power It 15 important to train your rider NOT to be a throttle blipper CLUTCH ASSEMBLY 1 Start with a new set of pre assembled washer stacks or a cleaned reassembled set of washer stacks and bolts CAUTION is also important that all three shoes are stacked the same See figure 32 2 Clean the threads of the stack bolt and the clutch with brake cleaner removing all old thread locking material 3 Assemble the stacks and shoes on the arbor using high strength thread lock material to the stack bolt and tighten to 16 Nm 12 ft lb 144 in Ib CAUTION Avoid allowing excess thread lock material to contact the spring washers and the clutch or the clutch is likely to malfunction 4 Clean the threads of the crank shaft and the clutch nut o Install the clutch arbor on the crank Making sure that the backing spacer in place on the crank 6 Apply high strength thread locking agent to the threads and install the clut
48. irflow around the stator e Ignition will overheat if the gap between the rotor and stator is not large enough There should be even clearance as the rotor rotates relative to the stator e Non resistor spark plug caps should be used Resistor caps will result in a weaker spark that will reduce performance e Make sure connections are free of dirt The proper ignition timing for this model of is at 0 040 before Top Dead Center that means 0 040 before the piston reaches the highest point of it s travel in the cylinder CAUTION Advancing the ignition timing will cause the engine to run hotter in turn causing power loss shortened clutch life and possibly lead to premature stator failure and can also cause detonation which can lead to premature piston and ring failure Tools recommended for timing service Compact motorcycle dial indicator 0079 e Universal clutch puller a universal puller that pulls the clutch main drive gear and rotor Part MCMUTL70O TIMING YOUR IGNITION 1 Remowve the spark plug 2 Insert the dial indicator into the spark plug hole 56 Or ote Do Figure 39 Lining up the line on the rotor with the line on the stator Remove the four bolts from the ignition cover Remove the water pump belt from the rotor and water pump shaft Turn the crankshaft counterclockwise until it reaches top dead center Set the dial indicator to zero Turn the crankshaft clockwise un
49. ission 78 Carburetor 20 Shock Clutch amp Kick Starter 24 Adjustments 72 Coolant System 21 Palo ru uiu I ILI 41 42 Sie UC 23 ERR 16 SE 28 Spark Plug 29 Keel 4 Wl 24 See E 4 Front 36 torque values Front Wheel 37 eil er 7 ES 18 Suspension Plastic 8 Seat 38 Adjustment 70 Rear Brake 39 Swingarm Parts 43 Rear 40 Top End Shock 41 42 WIR 27 Swingarm 43 EENEG 44 Top End 27 Torque Values 5 Triple Clamps 29 Transmission Plastic 8 Seat Parts 38 Specifications 4 63 M RO A Rear Brake EE 10 Adjustment 11 Troublesbootng 76 Bee 39 EE i Rear Wheel VIN Fe AGING 8 Eeler 40 WARNING ccc eee SM ees 62 Ee SS 79
50. ith more than 12 oz 295 cc will degrade performance 3 cylinder base gasket has been fitted for your engine The code number stamped into the engine cases will guide you to what thickness base gasket is required during a common top end service See the service section of this manual to correspond a code number with a base gasket part number 4 gt Evaluate the bikes jetting only after it has been warmed up to race temperatures 5 New chains will stretch on first use Never install a new chain prior to a race Always break them in during practice 6 Your Cobra motorcycle has a 10 digit VIN Vehicle Identification Number The first two digits indicate the model and the seventh indicates the model year MY Example CMxxxx7xxx is a 2007 MY CX50 JR 7 gt Because of the amount of heat generated by the clutch and engine during extended periods of riding it is advisable to remove the ignition cover afterward to allow the ignition to cool off The heat transfers through the cases and can damage the stator as it cools off because of lack of airflow around the stator If you ever need to weld anything on the bike disconnect the spark plug cap unplug the ignition disconnect the kill switch scrape the paint bare near the area to be welded and put the ground clamp as close to the area to be welded as possible Be sure the fuel tank and carburetor have been removed and safely located away from the welding process 9 1
51. k Mounts REF PART DESCRIPTION FACJ2012 FRAME CX50 JR HCBF1040 M10X40mm FLANGE HEAD BOLT MOUNTING BRACKET RADIATOR BOTTOM 6 55 SOCKET HEAD CAP SCREW M6 LOCK NUT 6 MCKGGROO GROMMET RADIATOR MOUNT 2 REQ D ON BOTTOM 2 ON TOP BRACKET MOUNTING BRACKET RADIATOR 2 REOD 8 HCBCO665 M6X65mm SOCKET HEAD CAP SCREW 9 HCBF0616 M6X16mm FLANGE HEAD 35 Parts Front Brakes PART DESCRIPTON 6 X BKKG0001 KITBRAKEPADS WITH E CLIP 02 8 BEEN 22 1 36 Parts Front Wheel Front Wheel PART DESCRIPTION WHEEL WITH BEARINGS SPOKE STYLE FRONT AXLE M5X12mm SOCKET HEAD SCREW 6 REQ D BRAKE ROTOR FRONT WHEEL SPACER LEFT SHORT BEARING WHEEL 2 REQ D SPACER WHEEL FRONT WHEEL SPACER RIGHT LONG WASHER AXLE 10 LOCK NUT AXLE 11 TUBE 10 3 Parts Plastic 8 Seat Plastic and Seat DESCRIPTION FRONT FENDER FLO YELLOW FRONT FENDER DENOTES COLOR WHT YEL FLO FENDER BOLT M6X16mm FLANGE HEAD 4 REOD NUMBER PLATE FRONT 2 FRONT PLATE DENOTES COLOR BLK WHT YEL 2 M6X16mm FLANGE HEAD BOLT FRONT NUMBER PLATE MOUNT 384 RADIATOR SHROUD SET LEFT 8 RIGHT FLO YELLOW 384 RADIATOR SHROUD SET x COLOR BLK WHT YEL FLO FUEL TANK NO OR M6X20mm PHILIPS HEAD SCREW SEAT amp SHROUD HOLD 5B SPACER SEAT 8 SHRO
52. ke over on its left side to add oil to the bike 5 Reinstall the oil fill plug NOTE Cobra has spent considerable time and money developing the proper lubrication to handle the harsh environment of the automatic clutch and transmission of this motorcycle Cobra s specially developed Cobra Venom 3 Shoe Clutch Milk Part MCMUGF32 was formulated to provide superior lubrication and cooling capability over extended periods of time and is the recommended lubricant for your Cobra motorcycle 10 Proper Chain adjustment Tools reguired for chain adjustment 19 mm wrench or socket 13 wrench or socket 1 Make sure that the rear wheel is aligned properly 2 A properly adjusted chain will have 50mm 2 free movement behind the chain block with no load on the bike figure 2 minimum of 12mm 1 2 free movement when the chain is at its tightest point 4 If the chain requires adjusting loosen the axle with a 19 mm wrench and tighten the chain by rotating the adjustor bolts clockwise CW or loosen the chain by rotating the adjustor bolts CCW 5 Retighten the axel bolt to 25 ft lb 34 Nm sd 6 Retighten the adjustor bolt Rear Brake Maintenance CAUTION Too little brake pedal free play will allow the brake pads to drag causing the pads to wear prematurely and possible engine component failures Too much free play will not allow the rider to apply the brakes quickly 1 Set pedal height position first the
53. leeve bolts of the 5GX provide a low uniform stress minimal heat transfer and allow channels for flushing the clutch fibers out of the washer stacks allowing a long time between part replacement provided you operate with 10 oz of clean Clutch Milk As before the new washer stacks are being double sorted at the factory They are first sorted by measured height Secondly each stack with bolt is sorted by measured engagement force The stacks in each set of three will measure within 0 05mm 0 002 There are many variables in an automatic centrifugal clutch These variables are set to world class standards from the factory but will change over time as the components wear relax and just plain get used Please see the Tuning Clutch portion of this manual for more helpful info Tools recommended for clutch service e Universal clutch puller a universal puller that pulls the clutch main drive gear and rotor Part MCMUTL70 omm T handle 125 Torx Accurate torque wrench in the range of 16 Nm 12 ft lb 144 in Ib Clutch nut removal tool ECMUOO78 amp piston stop MCMUTLO3 Cobra Shoe Clutch Milk Part MCMUGF32 CLUTCH REMOVAL 1 Drain the engine transmission oil and remove the clutch cover 51 2 Remove the clutch nut not left hand thread on the end of the crankshaft with the clutch nut removal tool 3 Attach the Universal Puller There are three 6mm clutch puller holes located on the ends of the center hub fig
54. lywheel nut or kick lever three revolutions to crush the solder wire to be measured CAUTION If you rotate the flywheel nut in a counterclockwise direction there is a risk of loosening the nut e Pull out the wire and measure the solder thickness at the thinnest location near its tip accurately with the thin tips of calipers e Adjust base gasket thickness as necessary to get the desired value Upon completion your final assembly squish clearance should agree with the chart below Measured Squish Clearance minimum These numbers only apply when measured as described above 0 020 0 026 0 50 0 65 Best performance Lose of Torque Over rev of damage performance 46 Engine Removal To service the bottom end transmission the engine must be removed from the frame Tools reguired 10 11 13 22 mm wrench 8 10 14 17 8 19 mm sockets 3 4 8 5 mm Allen wrench 7 mm nut driver flat or Phillip screwdriver for hose clamps Spring remover Flywheel clutch puller MCMUTL70 Clutch nut removal tool ZECMUOO78 CFD gear stop 004 Procedure 1 Remove the seat 2 Turn of the fuel at the petcock and disconnect the fuel line 3 Remove the tank 8 mm socket 4 Remove the carburetor from the inlet flat head or Phillips head screwdriver 7 mm nut driver Remove the silencer amp pipe Spring remover 8mm socket Locate a suitable container
55. me with the given shoes basket arbor and bolt This can be due to 1 Clutch spring stack is to short Wrong configuration e Sacked out over stressed washers e Too thin a flat shim in the stack 2 Spring rate too low wrong configuration with proper stack height 3 Clutch arbor shoulder bolt is too long If a clutch comes in too late it means that clutch spring stack is providing too much force to keep the shoes from being thrown out to the clutch basket at the proper time with the given shoes basket arbor and bolt This can be due to 66 1 Clutch spring stack to tall e Wrong configuration e Too thick a flat shim in the stack Spring rate too high wrong configuration with proper stack height Clutch arbor shoulder bolt is too short Clutch shoe material has worn too thin Clutch basket has worn too much and is too large of a diameter ees With the exceptions of component failures generally two things will occur 1 The clutch shoes will wear causing the clutch to engage later and 2 The springs will sack causing the clutch to engage earlier Typically the springs will sack at a quicker rate than the shoes will wear meaning that an un tampered clutch that worked fine will ultimately hit too early at some time When this occurs it is easily remedied with a new spring stack or a thicker flat shim Because the shoes have worn a thinner flat washer may be needed with the fresh new springs to allow proper clutch engagement
56. n 2 Set pedal free play Brake pedal height can be adjusted with the bolt and nut located under the rear of the brake pedal The free play is adjusted with the adjustable plunger on the end of the brake pedal 11 CAUTION Use only DOT 4 brake fluid Setting rear brake pedal position see figure 2b 1 Loosen the lock nut 10mm wrench 2 Adjust the brake lever stop 10mm wrench so that the lever is comfortably reachable in both a Standing riding position and Figure 2b b Sitting riding position 4 i 3 Tighten the lock nut 10 mm ES E wrench CAUTION Adequate pedal free play is required Lock Nut so that the brake pads do not drag on the rotor 1 MINIMUM Free Play Locking Clip Make sure that the free play locking clip is installed such that one must Clevis push forward toward the front of the bike to remove Otherwise the clip is Brake Adjust apt to come undone while riding Eccentric To adjust see figure 2b 1 Loosen lock nut 10mm 2 Undo the free play locking clip from around the brake adjustor plunger with your hand by pushing it forward 3 Slide the pin of the locking free play locking clip from the brake lever 4 Adjust as needed by rotating the clevis on the end of the adjustor NOTE Turning the clevis Clockwise will lengthen adjustor plunger removing free play from the system and turning the clevis Counter Clockwise will sh
57. ntil the engine comes up to full operating temperature CAUTION Make sure your riders foot is not resting on the foot brake while they are riding Maintenance A properly maintained machine is safer faster and more fun to ride It is important that you adhere to this maintenance schedule so as to promote the longevity of your Cobra Motorcycle Tips 1 Recommended lubricants a Cobra Clutch Milk is by far the best auto clutch lubricant It is a full synthetic lubricant that has been specifically formulated for Cobra s auto clutch and has e Exceptional film strength over petroleum based oils or synthetic blends e Extreme temperature tolerance e NO frictional modifiers e Dispersant package to keep clutch fibers in suspension so they can be flushed out when the oil is changed e Extremely low viscosity for minimal drag and windage b Bel Ray H1 R oil is the recommended premix oil because e 15 Ester base leaves a film on all parts at all times No metal to metal startups or corrosion potential e Exception film strength over petroleum based oils or other synthetic blends e Easily atomizes and burns completely e Does not fall out of suspension from premix in cold weather e Produces virtually no coking deposits leaving pistons rings and heads extremely clean with minimal pipe spooge 2 Filling your transmission with more than 8 0 oz 235 cc of lubricant will help to transfer heat from the clutch Filling w
58. on the CX50SR works under the principals of hydraulic damping and it features full adjustability to help tune the fork to meet each needs The CARD fork contains MXT Smart Leg technology that provides very progressive operation allowing a small bike to perform well on track surfaces ripped up by larger machines The key to Smart Leg technology is to understand that each leg has a different role The brake side leg features a conventional open cartridge This cartridge handles both standard compression and rebound damping duties Rebound damping is adjustable on the fork cap and compression damping is adjusted at the bottom of the fork The other leg the Smart Leg has no rebound damping and it contains both a speed sensitive compression damping mechanism as well as a position sensitive one This design allows for a firm low speed response controlling rapid chassis pitch which promotes stability and control The fork produces significantly less mid and high speed compression until it travels into the progressive speed sensitive portion of the smart leg The speed sensitive compression component is adjustable at the top of the fork The combination of the Smart Leg and the conventional leg allows the fork to be very supple throughout all low amplitude operation and yet take punishing hits producing a progressively increasing damping rate that slows the forks movement as it approaches full bottom Therefore the Smart Leg also acts a
59. orten the adjustor plunger adding free play to the system 12 Brake Bleeding Procedure Tools Required Front 110 Torx bit driver Cobra bleed kit 50031 Rear 3mm hex key Allen wrench T10 Torx bit driver Cobra bleed 0031 Procedure Remove the brake fluid reservoir cover Fill the syringe half full with brake fluid Remove the brake caliper bleed screw Attach the syringe to the brake caliper bleed access Keep the syringe oriented as not to allow air from the syringe into the system Using the syringe pull fluid through the system Use caution not to let the fluid in the reservoir to become low and introduce air into the system Using the syringe push fluid back into the system until the reservoir is full Repeat these actions of pulling and pushing fluid through the system a few times With the reservoir full engage the brake lever pedal and hold it there as if engaging the brakes While doing this pull on the plunger of the syringe Doing this will cause a vacuum in the system The vacuum will swell the air bubbles which assist in them moving throughout the system Continue pulling a vacuum and release the brake lever pedal careful not to allow the reservoir to become empty Once again engage the brakes while continuing to pull a vacuum When the reservoir is almost empty stop and push fluid back into the system Repeat these steps with the vacuum until no more air bubbles can be r
60. period operate the bike on the stand with a combination of idle and high RPM operation avoid prolonged high RPM but spin the rear wheel good at least once or twice per minute e Allow bike to cool e Ride for 15 minutes maximum avoid prolonged high RPM operation and avoid abusing the clutch with throttle blipping e Allow bike to cool and inspect bike for loose fasteners e Avoid prolonged operation at Wide Open Throttle for the next half hour e After 1 hour of operation o Check for loose bolts and nuts o Clean the carburetor bowl Change the transmission clutch lubricant Check CFD torque and adjust as necessary e After 8 hours of operation o Change the fork oil o Have a Certified Cobra Mechanic or suspension specialist change the shock oil e Your bike is now ready for the highest level of competition NOTE During break in the bike will likely lose some engine coolant through the radiator overflow hose Losing up to 4 oz 120 ml is normal Proper coolant level will cover the top of the radiator cores Removing the radiator cap and looking inside is the only way to check the coolant level Never remove the radiator cap of a machine that has a warm engine Burning and scalding could occur Starting Procedure Before starting the machine inspect the following Tire pressure Chain tension Coolant level Proper wear on chain rollers and sliders Handlebar tightness Throttle assembly movement cable adjustment Air Filter
61. raight line stability 1 5 Compression damping 1 5 1 Harder more damping slower adds resistance to the suspension motion when the suspension is compressing 1 5 2 Softer less damping quicker reduces resistance to the suspension motion when the suspension is compressing 1 6 Rebound damping 1 6 1 Harder more damping slower adds resistance to the suspension motion when the suspension is returning to full length 1 6 2 Softer less damping quicker reduces resistance to the suspension motion when the suspension is returning to full length 2 Rear shock 2 1 Preload adjustment 2 1 1 More preload greater distance less race sag 2 1 2 Less preload smaller distance more race sag 2 2 Shock spring 2 2 1 Stiffer spring stiffer throughout the travel 2 2 2 Less stiff spring less stiff throughout the travel 2 3 Compression damping 2 3 1 Harder more damping slower adds resistance to the suspension motion when the suspension is compressing 2 3 2 Softer less damping quicker reduces resistance to the suspension motion when the suspension is compressing 2 4 Rebound damping 2 4 1 Harder more damping slower adds resistance to the suspension motion when the suspension is returning to full length 2 4 2 Softer less damping quicker reduces resistance to the suspension motion when the suspension is returning to full length 1 1 70 Front Fork Operation The front suspension
62. rive ratio Chain Transmission clutch oil type Quantity Chassis Front tire Pressure Rear tire Pressure Front fork Fork oil type Fork oil amount Std settings Rear Shock std settings 35 75 908mm 10 254mm 23 9 607 2 stroke single cylinder valve Liguid cooled 50 50 antifreeze coolant distilled water 49 8 39 41 7 Electronic analogic advance Autolite XS61 4261 0 023 0 025 0 58 0 64 mm 0 040 1 0 mm Before Top Dead Center BTDC High octane pump gasoline Bel Ray H1 R 40 1 to 50 1 ARA 14 mm Dell Orto LUBRICANTS 55 92 16mm 0 5mm 0 63 0 020 Single Cobra 3 shoe 14 37 T 420 Cobra Venom 3 Shoe Milk 235 350 ml 8 1202 2 75 80 100 10 15 psi minimum 2 75 80 100 10 15 psi min 20 psi for hard pack or rocky conditions CARD 32mm USD Fully Adjustable w Smart Leg 2 5wt Bel Ray Fork Oil 145 ml omart leg 3out Compression and rebound 1 1 2 out Compression Low 7 High 7 No Rebound Adj Optional Suspension Components Weight of Rider Ib Fork Spring Shock Spring Less than 38 light 15 N mm SCMUOHO4 275 Ibin red KCCJ3221 SCMUOHOS 285 Ib in erede 21 Ib in 3 70 N mm yellow KCCJ3225 SCMUOHO6 295 Ib in EE 25 4 40 N mm white Specifications Torgue Values Torque Value Loctite Size amp Remarks Gussen 103 t3 mun
63. s a hydraulic bottoming control device Finally the large degree of adjustability in both legs allows the fork to be tuned to meet each size ability and type of riding they do motocross off road flat track etc Fork Damping Adjustments Tools required e Small flat blade screwdriver The speed at which the fork rebounds can be adjusted at the top of the conventional leg Turning the adjustment screw clockwise slows the rate at which the fork extends after being compressed and likewise turning the screw counter clockwise returns the leg to its extended position faster As shown in the figure S slower and F faster are etched into the cap as an adjustment guide HREBOUND ACLS MEHI At the base of the conventional leg is another adjustment screw that controls the amount of compression damping 71 CUOIPRESSION ADJUS TIVENT Turning this screw clockwise increases damping and turning it counter clockwise will decrease it This is illustrated by the HARD and SOFT in the figure at the right The Smart Leg cap is labeled Speed Sensitive Bottoming Control and this adjuster provides a range of control over how progressive the fork feels Turning the screw clockwise increases the fork s resistance to bottoming while turning the screw counter clockwise decreases it On the track this effect will be felt on sections where the fork is forced to move very quickly such as on harsh landings or w
64. tch will contain 11 individual springs and flat washer s configured as a 5 2 stack See figure 32 This clutch is designed such that it reconfigured by the customer to achieve different clutch engagements hits by changing washer counts and configurations CAUTION Generally reassemble the springs you removed them from the engine or as you received them from Cobra If you are unsure call the Cobra Technical Support Group 517 437 9100 and consult the experts 5GX CLUTCH ASSEMBLY REFERENCE DRAWING REF PART DESCRIPTION 1 0009 Set of three shoes springs bolts flat washers amp nuts 2 0014 Set Of three springs washers bolts amp nuts Not Shown CAMUOO02 Complete assembled clutch Arbor shoes and washer stacks SLEEVE INSTALLED ON SLEEVE BOLT 4 VA Sr it COMPLETE 5GX WASHER STACK 4 SLEEVE AND BOLT ASSEMBLY Figure 32 Some configuration of clutch spring stack Each spring stack contains multiple springs Belleville washers arranged into three four or five flying saucers or turned away against the flat washer s Shown is the 5 gt stack Total Flying Saucers Turned Away Std Flat HIT Springs or Cymbal or Dish Washer s Pairs Stacked VARIED HARD VARIED SOFTER Clutch adjustment washers Your Cobra comes stock with flat washer s at the bottom of the spring washer stack Cobra offers several thicknesses of thin adjus
65. til the dial indicator reaches 0 040 1 0mm from top dead center At this position the line on the rotor should align with the center of the stator at 5 o clock position on stator frame If not loosen the three 5mm bolts to adjust the stator N Figure 40 Using a dial indicator to measure piston height for setting ignition timing ROTOR INSTALLATION 1 pron Im Torque the nut on the rotor to 30 ft Ib 45 Nm with medium strength blue thread locking agent Recheck the timing following the procedure of timing your ignition Install the water pump belt back on Bolt the ignition cover back on Put the spark plug back in and firmly stick the spark plug cap onto the spark plug Cooling System Radiator fluid removal Remove the coolant drain plug 13mm bolt on the front of the engine cases 57 NOTE Inspect the old coolant for evidence of combustion byproducts black oil slick stuff or other things that may indicate a problem Tools recommended for impeller service Flat head screwdriver 13mm hex wrench 3mm hex key 4mm hex key omm hex key 8mm hex key Water Pump Installation tool MCMUTLO9 2010 and newer JR 8 King MCMUTLO8 2009 and older JR models e Slide hammer with e fitting to thread into threads on end of shaft M5x1 0 e single and double hook ends for removing plastic impeller e Dead blow hammer COBRA IMPELLER SERVICE INSTRUCTIONS 1 Remove radiator cap and drain en
66. tional components for your Cobra Motorcycle Rear Shock The rear shock is fully serviceable but it is recommended that only trained professionals should service your shock Contact Cobra for guestions and service of your CX50 SR shock 65 Tuning Clutch There are performance characteristics to observe and things to measure 1 Performance characteristics to observe a Clutch coming in too late i Engine rev s to high RPM before moving the motorcycle li Clutch never fully engages a reasonable straight stretch Basket turns blue in short amount of time b Clutch coming in too early i Motorcycle moves too soon when accelerating off idle li Motorcycle moves but not with much power Clutch fully engages before the power band kicks in 2 Things to measure that can have an effect a Spring washer configuration b Spring stack without flat washer c Thickness of flat washer d Individual spring washer thickness e Individual spring washer height Effective bolt shoulder length g Shoe thickness difficult to measure accurately can only be approximated by the size of the step where it sticks out of the basket h Basket has worn and is too large There ts a relationship between observed characteristics and the things that can be measured If a clutch comes in too early it means that clutch spring stack is not providing enough force to keep the shoes from being thrown out to the clutch basket at the proper ti
67. tment washers that allow clutch engagement tuning Increasing the flat washer s thickness increases the engine speed for clutch engagement thus increasing the abruptness of clutch engagement harder hit Conversely decreasing the flat washer s thickness decreases the engine speed for clutch engagement thus decreasing the abruptness of clutch engagement softer hit NOTE 2 Clutch shim kit includes each 005 010 015 and 020 shims along with 2 clutch to hub spacers and 2 thin clutch to hub spacers Use the table above to order adjustment washers Replace the stock washer with the proper combination of adjustment washers that delivers the desired clutch hit CAUTION is easy to prematurely damage the clutch and other engine components with improper clutch adjustment If you are unsure of how to adjust the clutch contact the Cobra Technical Support Group before making adjustments Clutch shoe wear e This can be measured by the overall diameter of the shoes installed on the arbor This measurement should be greater than 80 5mm e Ifthe clutch has been slipping and shows signs of glazing it is best to replace the shoes We have found that once the shoes are glazed even if deglazed with emery paper or a file the performance is reduced e The best way to prevent glazing is by not gearing too high changing the oil as specified and by not blipping the throttle Every time you blip the throttle you are work
68. to one higher or lower 75 Troubleshooting 1 Engine not behaving properly 2 3 4 5 b Carburetor top is installed backwards happens a lot The carburetor slide indexing pin is missing Wrong spark plug installed 8339 Champion to be used 04 or later amp no mods Needle clip is on top of plastic not below Air leak find where with carb cleaner or similar Ground wire or ignition leads have fault Engine is down on power f 9 Clutch engagement is set properly Jetting is incorrect Silencer needs repacked Exhaust pipe excess carbon buildup large dent in it Compression is low i Piston li Rings Reeds are damaged Ignition timing is incorrect Engine is excessively loud a Silencer needs to be repacked Engine cuts out at high RPMs a b d Stator bad Carburetor diffuser plate upside down install like a skirt Plugged fuel petcock Silencer core tube broken Engine won t start a Fuel i None in tank ls sour or bad Carburetor is dirty Ignition Spark plug fouled 76 6 7 Wrong spark plug installed 8339 Champion to be used 04 or later amp no mods 11 Spark plug cap off iv Engine Shut off kill switch is shorted v Bad electrical ground vi Stator winding damaged d Exhaust is plugged Overheating a Bad stator b Water pump pulleys or belt broken c Water pump impeller broken or bolt out d
69. ures 30 amp 31 4 Install each of the 3 6mm socket head cap screws clutch cover bolts can be used until each is similarly snug and the puller looks square to the end of the crank 5 One ata time tighten each of the 1 4 turn until the clutch pops off 6mm Puller hole 6mm Puller hole Apply heat here if necessary Puller hole Figure 30 Figure 31 Clutch puller installation CAUTION Do not use a jaw type puller CAUTION is possible to cause damage to the piston when using the piston stop Care must be used when removing and installing the clutch arbor and using the piston stop 6 If necessary apply heat to the center clutch hub CAUTION Do not heat the crankshaft threads or the aluminum shoes 7 Keep tension on the puller as you are heating it The clutch will often pop off under tension from the puller and it will be very hot 52 CLUTCH WASHER STACKUPS Once the clutch is removed and cool to touch carefully put it into a vice and remove the center shoulder bolt out of each clutch shoe You WILL have to heat the center hub again to remove the bolts Once you get a bolt loosened carefully remove it with the shoe and observe the way the spring washers are stacked Clean the washers and bolt if you intend to reuse CAUTION lf you do not apply heat to the arbor near the clutch bolt threads you will very likely break the Torx bit upon attempted removal The spring stacks in your Cobra clu
70. ut Tighten the jamnut Tighten the fork cap to the fork leg outer Pump the fork leg several times to verify that it operates smoothly 0 Install each leg back into the triple clamp Torque each pinch bolt to 8N m 6 ft lb making sure both legs are set to the same height in the clamps 11 Reinstall the brake caliper 12 Reinstall the front wheel 25 ft lb 34 Nm Cobra Frictional Drive V3 CFD The Cobra Frictional Drive CFD is essentially an adjustable slip clutch that dissipates torque spikes transmitted from the rear wheel to the rest of the drive line and engine Instead of these torque spikes potentially damaging internal components the CFD allows the transmission to slip with respect to the engine For this to occur the CFD must function properly by slipping above a minimum torque value Ne ee gt iuum The safe minimum slip torque of the CFD should be checked every 2 hours of operation after break in 16 The slip torque value should be above 60 ft lb 81 Nm measured at the sprocket To properly measure the minimum torgue at which the CFD Cobra Frictional Drive slips 1 Access the slip clutch by draining the oil and removing the cover exposing the CFD 2 Brace the CFD gear from turning with a suitable device Cobra tool EAMU0004 or similar 3 Install the Sprocket Socket CFD torque checking tool MCMUTL15 on the sprocket and secure with the supplied screw and ensure that the tool is complet

CX50 JR Owners Manual

Contents

Download Pdf Manuals

Related Search

Related Contents