DC65 - King Cobra of Florida
Contents
1. 5 Transmission Lubricant Replacing 14 Troubleshooting General 44 Jetting 27 Suspension 34 Tuning Carburetor 27 Suspension 34 VIN reading 12 WARNING eene 2 Water pump 25 452. 16 Fuel uuu 11 Fuel System arts lp 25 SENICE dA udo 25 General Tips 12 Ignition PAINS o uu mm Ou 24 24 Jetting 1517976 i ei Sua Au i 5 Troubleshooting 27 Lubrication Recommended 5 Maintenance Schedule 13 dut a 13 Oil Recommended 5 Optional Components 9 Parts Bottom end 20 CTC MUT MNT 21 Ignition 24 Inlet eeu deutet 25 HOS 25 Bison 20 Water 25 11 Rear Brake Adjustment 17 PRESS RE 25 Spark Plug Recommended 5 Specifications 5 Torque Values 6 11 Troubleshooting 34 an Sa 34 12 DEIWICS 20 Torque NASSIS 7 Engine u sauna 6 Transmission Service 20 Specifications
3. 1 4 1 Rise in clamps for quicker turning 1 4 2 Lower in clamps for improved straight line stability Rear shock 2 1 Shock length eye to eye 2 1 1 Shorter shock length lower ride height for shorter riders 2 1 2 Longer shock length higher ride height for taller riders 2 2 Preload adjustment 2 2 1 More preload greater distance less race sag 2 2 2 Less preload smaller distance more race sag 2 3 Shock spring 2 3 1 Stiffer spring stiffer throughout the travel 2 3 2 Less stiff spring less stiff throughout the travel 2 4 Compression damping 2 4 1 Harder more damping slower adds resistance to the suspension motion when the suspension is compressing 2 4 2 Softer less damping quicker reduces resistance to the suspension motion when the suspension is compressing 2 5 Rebound damping 2 5 1 Harder more damping slower adds resistance to the suspension motion when the suspension is returning to full length 2 5 2 Softer less damping quicker reduces resistance to the suspension motion when the suspension is returning to full length 43 Troubleshooting 1 2 3 4 5 6 Engine not behaving properly a Carburetor top is installed backwards happens a lot b The carburetor slide indexing pin is missing Engine is down on power a Clutch engagement is not set properly Jetting is incorrect c Silencer needs repacked Exhaust pipe i excess carbon b
4. Or the pressure may deform the float Do not use a strong carburetor cleaning solution which could attack the parts of the carburetor instead use a mild high cleaning solution safe for plastic parts 5 Immerse all the metal parts in a carburetor cleaning solution 6 Rinse the parts in water 7 After the parts are cleaned dry them with compressed air 8 Blow out the fuel passages with compressed air 9 Assemble the carburetor 10 Install the carburetor onto the motorcycle ES7 Exhaust The pipe is a crucial element to a motorcycle Any kinks dents or damage done to the pipe will result in a performance loss NOTE Be sure to take the pipe off and remove 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 the pipe will decrease due to carbon build up So it is essential to clear the residue CAUTION For optimum performance it is important to repack the silencer Signs of your silencer needing to be repacked are e is louder than normal e A loss of power 26 Tuning Tuning 1 Carburetor Topics included are 1 Jetting Decisions 2 Jetting Changes C1 Jetting Decisions 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 w
5. Remove the jet access plug from the bottom of the float bowl 17 mm wrench 5 Remove the jet 6mm socket or jet wrench 6 The jet size is stamped in the side CAUTION When making main jet changes make changes in single step sizes and always take the conservative approach if you are unsure experiment rich before experimenting lean Installation 1 Lightly seat the new jet 6 mm socket or jet wrench 2 Reinstall the jet access plug in the bottom of the float bowl 17 mm wrench 3 Reinstall the carburetor properly in the inlet and air boot CAUTION Make certain that the carburetor completely inserted into the inlet and that the air 31 boot is pulled at least 8mm over the inlet of the carburetor body To replace the pilot jet REQUIRED TOOLS e Flat blade screwdriver 17mm wrench Removal 1 Insure that the fuel petcock is turned to off 2 Loosen the hose clamps at the front and rear of the carburetor screwdriver 3 Rotate the carburetor so that the float bowl is exposed may need to dislocate from the air boots 4 Remove the jet access plug from the bottom of the float bowl 17 mm wrench 5 Remove the jet flat screw driver 6 The jet size is stamped in the side CAUTION When making main jet changes make changes in single step sizes and always take the conservative approach if you are unsure experiment rich before experimenting lean Installation 4 Lightly seat the new jet flat screw
6. The float height is within proper specification proper measuring technique is described later in this section NOTE Perform all jetting changes on a motorcycle that has been warmed up to proper operating temperature O O O OOO The carburetor on your Cobra motorcycle is quite adjustable Figure 8 shows its range of adjustment and in particular what adjustable component affects what range of operation specifically throttle position Clip Position Straight Dia Needle Taper Effectiveness X Throttle valve ZA Cutaway gt LMS Air Screw Stow Jet Slow Jot IDLE 1 8 1 4 1 2 3 4 Throttle Opening Figure 8 AIR SCREW ADJUSTMENT Adjust for maximum idle speed The air 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 28 screw driver for adjustment After adjusting for maximum idle speed use the idle screw to adjust the desired idle speed NOTE If the air screw requires more than 3 turns out replace the pilot jet for one that is one size leaner smaller number then readjust the air screw Figure 9 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 idl
7. 8 hour break in period Be sure to use 93 octane pump gas or Sunoco 2 with Cobra s specially formulated Cobra Venom 2 cycle Race Oil Part MCMUOLO2 CAUTION Failure to use proper fuel or oil 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 First hour of operation Follow the starting procedure listed in this manual Avoid prolonged operation at Wide Open Throttle e After 1 hour of operation o Check for loose bolts and nuts on the bike and retighten as necessary proper toque values are listed under Specifications o Clean the carburetor bowl o Change the transmission clutch lubricant Replace the fuel filter After 8 hours of operation Change the fork oil Have Certified Cobra Mechanic change the shock oil e Your bike is now ready for the highest level of competition Starting Procedure Before starting the machine inspect the following e Insure that the fuel tank contains an adequate volume of fuel oil mixture to complete the distance required Sunoco MO2X or 93 octane pump gas with Cobra s specially formulated Cobra Venom 2 cycle Hace Oil Check for proper tire pressure in both tires Observe the chain tension and adjust if necessary Observe the coolant level and fill if necessary Verify that the chain rollers do not have improper wear Inspect the frame for Crac
8. CAUTION Breuer He run CN connections are free 2 24 ES5 Cooling System Parts list coming soon ES6 Fuel amp Air System Parts list coming soon Reeds CAUTION Thereeds must lay flat on the reed cage e reed tips aren t lying flat replace them immediately The reeds must have a tight seal on the reed cage e f 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 See figure 7 The presence of light indicates that the reeds should be replaced or possibly turned over umor cr Figure 7 The presence of light indicates that the reeds should be replaced or possibly turned over 25 Carburetor Cleaning Clean the carburetor in a well ventilated area and take care that there is no spark or flame anywhere near the 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 Make sure the fuel is shut off Remove the carburetor Drain the fuel in the carburetor Disassemble the carburetor Bum CAUTION Do not use compressed air on an assembled carburetor
9. cod eot cae e ma tras atre decide alee deeds 16 M4 Clutch lever adjustment duo ee eere do ee 16 M5 Rear brake 17 6 Air Filter Cleaning ER D m 18 o Ro a a n te i ve 19 Engine Paris SBrVI GG coc evt aec Er an iat ES Ge 20 ESI TODEIGPASFIS toto be uhay dae 20 ES2 Bottom end amp Transmissions oe eoa ti ober ee 20 53 Clutch and Shifter components sese 21 to m ux 24 ES5 Cooling GySIBITI S D 25 ES6 Fuel amp Air System t MdL 25 27 dit remate ae ded 27 Jetting 9B lero bol fel 27 Jeturig Oates d M 30 Tuning 2 SUSDOISIOD 34 1 S sp nsiom G ld elleS oracle uu e 35 2 Proper Suspension Adjustments for Your 36 Symptoms of Incorrect Suspension 40 4 Proactive Suspension Adjustments eese 41 5 How to Adjus
10. driver 5 Reinstall the jet access plug in the bottom of the float bowl 17 mm wrench 6 Reinstall the carburetor properly in the inlet and air boot CAUTION Make certain that the carburetor completely inserted into the inlet and that the air boot is pulled at least 8mm over the inlet of the carburetor body To adjust the jet needle clip position REQUIRED TOOLS e Flat blade screw driver 1 Insure that the fuel petcock is turned to off 2 Using a flat blade screwdriver loosen the hose clamps to the front and rear of the carburetor 3 Work the carburetor from the inlet and airbox 4 Detach the fuel line from the top of the carburetor 5 Detach the carburetor from the cable and slide by unscrewing the cap off the top of the carburetor CAUTION The jet needle is attached to the end of the slide Take care not to abuse it CAUTION The carburetor will likely still hold some flammable fuel which is likely to drain out when laid in a horizontal position so place it in a well ventilated area where it 32 may drain 6 To remove the slide from the cable hold the slide in one hand and compress the spring into the cap with the other 7 While compressing the spring hold the slide upside down such that the retaining plate drops free 8 Snake the cable through the proper grooves to remove the cable from the slide 9 With the slide free from the cable lightly push on the pointed end of the jet needle to remove it from
11. energetic rider Make notes Write down what works and what doesn t work for a particular track The suspension on this Cobra Motorcycle has many degrees of adjustment This is to provide a machine which can be set up most precisely to the rider and tracks requirements Unfortunately this also means that there many ways to do it wrong You will achieve the best results if you 1 Read and understand this whole suspension tuning portion of the manual and 2 Precisely follow the steps spelled out in the following section called Proper Suspension Adjustments for Your Rider and If you get confused overwhelmed or feel that you have just made things worse take a step backward in adjustment to what DID work best Perhaps even requiring you to return to stock settings 4 f all else fails call the Cobra Technical support hotline 330 549 9603 35 S2 Proper Suspension Adjustments for Your Rider Free length measurement of available suspension travel with bike on stand wheels suspended No load sag amount that the free length measurement is reduced by taking the machine off the stand fluids filled to race quantities Race sag amount that the free length is reduced with a rider onboard in riding Fork position fluids filled to race quantities Height C Ride height The height of the bike while the rider is onboard Fork height The amount of fork tube extending above the top triple clamp figure
12. facilitate motorcycle service Tools recommended for air filter maintenance e Foam filter oil Procedure 1 Removed the front fastener from the left side number plate Hex key NOTE This fastener holds a spacer between number plate and the frame which will drop into the airbox when the fastener is pulled from the number plate Merely grab the spacer with one hand while removing the spacer from the number plate with the other 2 Rotate the number plate counter clockwise downward exposing the aluminum air box side plate Remove the two fasteners holding the air box side plate Hex key Separate the air filter from the carburetor a Clean the filter with cleaning solvent and then again with hot soapy water Allow it to dry thoroughly Saturate with foam filter oil and remove excess Do not clean the air filter with gasoline or other highly volatile petroleum product Cleaning solvent diesel fuel or kerosene would be preferred but caution should still be taken DEO OV NOTE The biodegradable air filter oils greases and cleansers work acceptably with this Cobra Motorcycle CAUTION Cobra does rot recommend using the spray on air filter oils due to their limited saturation NOTE It is very important to keep the air filter clean and properly oiled with high quality water resistant foam filter oil It s very important to oil your filter consistently each time because varied amounts of oil will change
13. friction stiction forces 5 Calculate the Race Sag by subtracting the Race Length from the Free Length and record it in the table 6 The desired number is 75 mm 3 0 Figure 14 38 Length Length Target 75 mm 3 0 Length Target 19 mm 3 4 Calculate as Calculate as Free Length Free Length Race Length No Load Length Table 1 Sag calculations 7 lf your race sag number does not equal 75 mm 3 0 adjust the preload on the shock to achieve this value 7 1 your race sag is greater than 75 mm 3 0 increase the shock preload by one turn 7 1 1 Loosen the shock preload lock nut 7 1 2 Turn the preload adjuster in towards the spring one more turn 7 1 3 Resecure the lock nut 7 2 your race sag is less than 75 mm 3 0 reduce the shock preload by one turn 7 2 1 Loosen the shock preload lock nut 7 2 2 Turn the preload adjuster back from the spring by one turn NOTE If you unload the spring while performing this task you must purchase a softer spring 7 2 3 Resecure the lock nut 7 3 Remeasure the race length as described above 7 4 Repeat this procedure until you are sufficiently close to the target value STEP 4 Proper No Load Sag Tools required Measuring tape Shock preload spanner Calculator or the ability to subtract without one NOTE Always be consistent with measuring units Stick with inches or millimeters mm Adjustment Procedure 1 Again measure the distance be
14. rear of the carburetor Work the carburetor from the inlet and airbox Detach the fuel line from the top of the carburetor Detach the carburetor from the cable and slide by unscrewing the cap off the top of the carburetor CAUTION The jet needle is attached to the end of the slide Take care not to bend or abuse it Remove the float bowl by removing the two Phillips head screws CAUTION Perform step six in a well ventilated area and over a small pan as some flammable fuel is likely to drain from the bowl as it is removed from the carburetor 7 Hold the carburetor with the float bowl removed as shown in figure 10 measuring from the bottom of the float to the carburetor body gasket surface 30 Figure 10 NOTE When measuring the float height the float should be resting but not depressing the spring loaded float valve pin his can be done by tilting the carburetor until the float tab just makes contact with the valve pin If adjustment is needed bend the metal tab on the float arm until correct height is obtained 19 mm 0 5mm 0 75 0 020 To replace the main jet REQUIRED TOOLS e Flat blade screwdriver 17 mm wrench e 6mm socket or Keihin jet wrench Removal 1 Insure that the fuel petcock is turned to off 2 Loosen the hose clamps at the front and rear of the carburetor screwdriver 3 Rotate the carburetor so that the float bowl is exposed may need to dislocate from the air boots 4
15. should be done professionally Cobra trues every crank before it leaves the factory and also welds the pin to keep it true If there are any problems send the engine in or call tech support 830 549 9603 to determine what the problem is CAUTION e f you split the cases check the gear tooth faces for chapping amp signs of fatigue e Check the small needle bearings for fatigue If 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 e Needle bearings should be replaced every racing season 20 Clutch and Shifter components ES3 81 SX LL Figure 5 HCBB0612 6 2 SOC BUT BOLT ZINCYEL ECDCO022 5 DRUM 65CC 0 02 ECMUO016 BEARING 5OCRANK 0 ECDCO024 SEAL CRANKSHAFT DC65 1 1 1 1 0073 CRANK DRIVE GEAR DC65 ECDCO036 SNAP RINGEXT 16MM SPRINGRET ECDCO075 IMPELLER 65CC WATERPUMP ECDCO064 CLUTCH BUSHING DC65 INNER ECDCO165 CLUTCHBASKETBILLETDO65 1 1 m rm rn m rm O O O O O O O Z UO O O O O C IO IS 565 65 6 56 5 5 lt S 6 mm OJO gjg O O S alo olo OR 5X25 SOCKET HEAD CAP SCREW IECDCO020 CLUTCH PUSH ROD S ECDC0037 SNAP RING EXT 15MM IDLER RET ECDC0032 GEAR KICK STARTER IDL
16. 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 41 S5 How to Adjust the Suspension Preload height Shock preload Mechanical preloading adjustment Figure 15 Shock Damping More damping harder slower O Less damping softer faster Figure 16 Shock Length The shock on your Cobra Motorcycle has an adjustable eye to eye length It is not to be Groove extended any longer than when one groove is visible below the locknut after tightening Figure 17 42 S6 Suspension Reference 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 1 3 Gas pressure always bleed off any pressure 1 4 Fork height see figure
17. xxx x2xxx is a 2003 MY DC65 Maintenance Schedule amp Tips It is important that you adhere to this maintenance schedule so as to promote the longevity of your Cobra Motorcycle Between each ride o Inspect the fuel filter for contaminates o Check the air filter clean and re oil as necessary o Insure the smooth operation of the throttle cable throttle soundly clacks shut o Check for frayed strands of the throttle cable inside the throttle housing and replace if necessary Check for adequate tire pressures and adjust if necessary Check all nuts and bolts for proper torque and re torque if necessary Spray all moving parts with WD40 or other light oil Check drive chain for Proper tension and adjust if necessary Adequate lubrication and lubricate if necessary o Insure that the ignition stator and rotor are clean and dry o Check the frame for cracks in the metal or cracks in the paint that might indicate that the metal has been stressed beyond it s safe limits Replace or get properly rewelded as necessary Every 2 hours of operation Replace the transmission oil Every 10 hours of operation o Replace the fork oil o Have the shock oil replaced by a Certified Cobra Mechanic CAUTION 1 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 t
18. 11 Figure 11 STEP 1 Fork Spring Selection The standard fork spring should be fine for the typical Cobra rider Although depending on your racers weight and alternative spring may suit him her better If your child weights more than 85 Ib 39 kg then the optional stiffer spring is recommended If you child weights less than 60 Ib 27 kg then the optional softer spring is recommended STEP 2 Proper Ride Height Taller riders will want the ride height set as high as possible Conversely shorter riders will want to set ride height as low as possible Keep in mind that you need a front to rear balance The bike is balanced when the rear frame spars are vertical A proper ride height is established by first adjusting the rear of the bike to the desired height and then readjusting the fork height to rebalance the bike The height of the rear of the bike is adjusted with the shock eye to eye length Adjust the ride height such that the rider feels most comfortable touching the ground when not moving The shock on your Cobra Motorcycle has an Groove adjustable eye to eye length It is not to be extended any longer than when one groove is visible below the locknut after tightening Figure 12 36 Adjustment Procedure 1 Adjust the height of the rear of the bike 1 1 Remove the shock as covered in the service portion of this manual 1 2 Using a vice and a thin 17 mm wrench adjust the length of the shock 1 3 Reins
19. 2003 DCx65 Owners Service Manual CHAMPIONS START HERE For parts orders contact your local dealer To locate your closest Cobra dealer log on to www cobramotorcycle com or call 330 549 9600 If you need technical assistance contact your local dealer or call the Cobra Technical Support Hotline at 330 549 9603 Cobra Motorcycle MFG Inc 11511 Springfield Road North Lima Ohio 44452 MCDC2003 1 1 DISCLAIMER OF WARRANTY This motorcycle is sold as is with all faults obvious or not There are no warranties expressed or implied including any warranty of merchantability and warranty of fitness for any particular purpose WARNING THE COBRA DC65 IS A COMPETITION MODEL ONLY AND 15 NOT MANUFACTURED FOR NOR SHOULD IT BE USED ON PUBLIC STREETS ROADS OR HIGHWAYS THE USE OF THIS BIKE SHOULD BE LIMITED TO PARTICIPATION IN 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 TH
20. AT WEIGH MORE THAT BE SURE THAT THE RIDER ALWAYS WEARS ADEQUATE SAFETY GEAR EVERYTIME HE OR SHE RIDES THEIR COBRA MOTORCYCLE IMPORTANT SAFETY NOTICE A WARNING 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 A NOTE provides key information to make procedures easier or clearer Table Of Contents General a eo atia 5 Specifications Cere Als eve act 5 Specifications Torque Values esse aaa ibt cla 6 Specifications SUIS GINS ada ctl de les 8 Optional Components t 9 Break In Procedure 10 Starting Procedure tot ud 11 General C 12 13 ere gem IDS 13 M1 Replacing Transmission Lubricant senes 14 M2 Chain adilsltTiellls 15 M3 Front brake rie
21. ER DC65 23 33 ECDC0059 BOLT SHOULDER M6X11 8X5SB L CWFO501 CBB0001 DC0063 ECDCO057 LEVER NEUTRAL POSITIONING DC0035 DC0058 DC0060 m O g Q a N ECDCO035 SNAP RING EXT 12MM GEAR RET LEVER DRIVE GEAR POSITIONING SCREW M6X16PF ECDCO056 BEARING RETAINER PLATE ECDCO052 0 060 SCREW M6X16PF JECDCO038 RAMP GEAR DC65 ECDCO055 SHIFTER SPRING ECDC0054 SHIFTERSHAFT O O O i O ECDC0033 GEARKICKSTARTER DC65 1 1 1 1 ECDCO167 CLUTCH BASKET BUSHING OUTER ECDCOO7 PLATE CLUTCH SPRING 00650 22 rm rr eie o m o 7 10 11 12 13 14 15 16 17 18 19 20 21 22 24 25 26 27 28 29 30 31 32 34 35 36 37 38 39 40 41 42 4 5 6 7 8 9 m O g Q o o m O g Q 43 rm rm OJO gjg O O eje c AIO m O 2 Oo 2 m O g Q 4 4 4 4 4 ITI O 5 a 4 Figure 6 Clutch cover components 6 ECDC0046 KICKSTARTERLEVER DC65_ 8 ECDC0078 SEALKICKSTARTER 066 9 ZCMU0001_ GASKET OILFILLPLUG ALL 505 23 ES4 Ignition Za Figure 6 we Ignition components 6 601 WASHER FLATSMM 8 038 3 8FLATWASHER 9 ROTOR 10 00007 STATOR INCLUDED WITH SHIFTER LEVER
22. ION The damper rod is hollow and will break if the nut is over tightened 4 Reinstall the for cap into the fork leg 5 ft lb 6 7 Nm 5 Reinstall the fork legs into the clamps 6 ft lb 8 Nm 6 Reinstall the brake caliper 6 Reinstall the front wheel 25 ft lb 34 Nm Engine Parts Service At this time the service instructions for are not yet available your Cobra Motorcycle If you don t feel comfortable with the service work simply take your engine out of the frame and sent it to Cobra Precision Engines 11511 Springfield Road North Lima Ohio 44452 Cobra s technicians will go through the entire engine replacing gaskets bolts any old part that is worn The engine will be rebuilt using the same precision gauging and assembly fixtures as when it was assembled new Before being returned the engines performance will be measured on a dynamometer to ensure that your engine is operating at its highest potential All this for one low nominal fee plus cost of parts Call 330 549 9603 for details ES1 Top End Parts Parts list coming soon ES2 Bottom end amp transmission Parts list coming soon 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 and the rest of the engine Do not try to true the crank yourself Truing the crank
23. e 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 pt 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 or roll on 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 to one higher or lower 29 C2 Jetting Changes STOCK CARBURETOR SETTINGS 19 mm 0 5mm 0 75 0 020 float height Air screw 1 2 turn out 38 pilot jet JJH 3 3 position from top jet needle 128 main jet To check and or adjust float height REQUIRED TOOLS 6 Flat blade screwdriver 1 small Phillips screw driver Accurate measuring device Insure that the fuel petcock is turned to off Using a flat blade screwdriver loosen the hose clamps to the front and
24. e Measuring device Procedure 1 Loosen the rear axel nut two 19 mm wrenches 2 Adjust the chain adjusters in the end of the swingarm clockwise for tighter chain until proper chain tension 37 42mm 1 50 1 63 is achieved 13 mm wrench See figure 2 for proper measurement location NOTE This measurement is to be made with the motorcycle setting on a stand and the rear wheel suspended in the air while lifting on the chain 37 42 mm 1 50 1 63 chain center top of swingarm behind chain block 3 From back sight down the length of the chain to confirm that the rear wheel is running true rear sprocket is not forcing the chain to turn 4 Verify that the wheel is all the way forward against the adjusters 5 One way to do this is to place a shop rag between the chain and sprocket while rotating the wheel backwards figure 3 thus pulling the wheel forward Figure 3 6 Tighten the rear axel nut to 25 ft lb 34 Nm two 19 mm wrenches Rotate the wheel forward and remove the shop rag M3 Front brake adjustment Tools recommended for front brake maintenance e 10mm open end wrench 3mm hex key CAUTION Adequate lever free play is required so that the brake pads do not wear prematurely 1 _ Loosen the lock nut 10mm wrench 2 Screw the adjuster in Clockwise to remove free play or out Counter Clockwise to add free play 3mm hex key M4 Clutch lever adjustment The clutch
25. eather conditions altitude fuel variations and or engine modifications CAUTION Proper jetting is very important for engine performance and engine life Symptoms of improper jetting are listed below e Symptoms of incorrect oil or oil fuel ratio Poor acceleration Misfire at low engine speeds Excessive smoke Spark plug fouling Excessive black oil dripping from exhaust system Symptoms of too rich a fuel mixture Poor acceleration Engine will not rev 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 Symptoms of too lean a fuel mixture o Pinging or rattling o Erratic acceleration o Same actions as running out of fuel O O OOO O OO OO 0 High engine temperature White spark plug when removed for inspection 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 27 Environmental and altitude related mixture adjustments Condition Mixture will be Required adjustment Richer Leaner Richer Leaner None Leaner Leaner Richer NOTE e Before making any carburetor jetting changes verify that You are using the proper fuel and oil 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
26. he terrain Properly adjusted suspension instills confidence in the rider While tuning the suspension keep the following important points in mind If the machine is new the suspension will require a couple of hours of break in time Adjustments made during this time may need to be redone after break in Before making adjustments be sure that the machine 15 properly maintained lubricated and in fine working order The most important factors to consider when adjusting the suspension are 1 rider weight 2 rider ability and 3 track conditions Also consider your particular rider s style and personal riding position Before making drastic changes to suspension settings consult a riding expert to ensure that an improper riding style or body position is not the cause of the problem The front forks are designed to operate without any gas pressure Continually bleed off any pressure that builds up during riding or this will effect the feel of the front forks A properly adjusted machine is a balance of front and rear suspension adjustments Adjustments to one end may require compensating adjustments to the other end Adjustments to improve the feel of one portion of the race track may adversely effect the feel in another portion of the track Make small adjustments to improve the feel at a problem area but continually evaluate the effects of those adjustments on all other areas A tired rider will behave differently than an
27. ing agent applied to the threads Specifications Suspension 1 2 3 4 setting Fork Oil 5 wt amount 118 ml Shock Spring Preload Preloadheight lodo EM from full damp Pee lee from full NE Optional Components e Carburetor jets e Sprockets o Front o Rear e Suspension Springs Weight of Rider 10 Fork Shock Spring LessthanS1 than 51 SCDC0285 285 0 285 Ib in blue 14 Ib in Ib in SCDC0350 350 Ib in 350 Ib in Damping Rate Fork Valving Fork Valving Shock Valving Compression Rebound kit base valve mid valve Soft fast fast KCDCBVO1 KCDCMV01 2 1 Hard slow KCDCMV03 SCDCOHO1B e Flywheel weights o Middle weight ECDC0200 o Heavy weight ECDC0201 Break In Procedure Your Cobra Motorcycle is a close tolerance high performance machine and break in time is very important for maximum life and performance The DC65 can be ridden hard after the first 12 hour break in time but it is recommended that no adjustments are made to the carburetion or suspension until the full 8 hours of bike break in has elapsed Also after the engine transmission and drive train have been broken in for the full 8 hours the bike will be faster Use a fuel oil mixture of 32 1 for the full
28. ks in the metal Cracking paint which might indicate overly stressed material e X Verify that the handlebars are tight Check the throttle for Smooth operation and sound closing Frayed strands of the cable inside the throttle housing e Check for loose bolts and nuts and re torque as necessary e X Verify that the air filter is clean and properly saturated with oil e Tur the fuel by rotating the fuel petcock knob to the vertically downward position reserve position is horizontally forward CAUTION For best results from your Cobra Motorcycle use only the recommended fuels Testing has shown that most race fuels actually degrade performance When your pre ride inspection is complete the bike may be started For a cold engine follow this procedure 1 Reaching down to the carburetor on the left side of the bike pull up the black choke knob and rotate it so that it locks in this up position 2 Kick start the engine 3 Rev the engine in short spurts turning the throttle no more than 1 4 open until the engine will run without the choke 4 Verify a functional engine shut off switch by shutting off the engine 5 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 when it s cold or slightly warmed up Cobra recommends that you tell your child to take it easy the first couple of minutes i
29. lever adjuster requires no tools Rotate the red adjusting knob in Clockwise to remove free play or out Counter Clockwise to add free play M5 Rear brake adjustment Tools required 10 mm wrench 1 Set pedal position first then 2 Set pedal free play Setting rear brake pedal position see figure 4 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 b Sitting riding position 3 Tighten the lock nut 10 mm wrench lock free play locking clip clevis position adjuster lock nut Figure 4 Setting rear brake pedal free play CAUTION Adequate pedal free play is required so that the brake pads do not wear prematurely To adjust see figure 4 1 Loosen the lock nut 10mm 2 Undo the free play locking clip from around the brake adjuster 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 adjuster plunger NOTE Turning the clevis Clockwise will lengthen the adjuster plunger removing free play from the system and turning the clevis Counter Clockwise will shorten the adjuster plunger adding free play to the system 17 6 Air Filter Cleaning This Cobra Motorcycle comes with a unique air filter air boot unit designed to
30. lues Value Size amp Cylinder head nuts 2 14 x 20 Engine oil drain 8 1 25 Engine oil fill 14 1 0 Spark Plug 14 x 1 25 Crank case half i 6 x 1 0 Crank case cover 6 1 0 Flywheel rotor nut 10 x 1 25 G Clutch hub 10 x 1 25 G Units of mm unless otherwise specified G denotes the use of wicking bearing retainer green thread locking agent to applied to the mating surfaces of the two components but not the threads SP 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 Value Size amp CHASSIS Fastener Remarks Front axle nut 12x 1 25 Front brake caliber 8x 1 25 Front brake rotor 6 8 6 x 1 0 B Triple clamp bolts 6 8 6x1 0 Fork cap 5 1 25 x 18 Steering head 1 0 x 12 R Handle bar mounts 8x 1 25 Handle bar clamps 8x 1 25 Front engine mount 8x 1 25 Rear brake lever pivot 8x 1 25 Subframe fasteners 8x 1 25 Upper shock mount 10x 1 5 Lower shock mount 10x 1 5 Swingarm pivot 14x 2 0 Rear axle nut 12x 1 25 Rear sprocket bolts 8 x 1 25 B Rear brake caliper bolts 8x 1 25 Rear brake rotor bolts 6 x 1 0 B Units of mm unless otherwise specified R designates that the application requires the use of high strength red thread locking agent applied to the threads B designates that the application requires the use of medium strength blue thread lock
31. n practice until the engine comes up to full operating temperature Make sure your engine is properly warmed up before racing General Tips Always wear a helmet and other protective riding gear Cobra recommends that you tell your child to take it easy the first couple of minutes in practice until the engine comes up to full operating temperature Make sure your riders foot is not resting on the rear brake pedal while they are riding Evaluate the bikes jetting only after it has been warmed up to race temperatures A properly maintained machine is safer faster and more fun to ride When washing the bike be careful to not directly aim the hose at the bottom edge of the seat or water is apt to enter the airbox Some people have found cable ties zip ties more favorable for securing the rear brake line to the swingarm Also some people are moving the rear brake line hose between the master cylinder and the reservoir from it s stock position to a position slightly more forward and securing it with a cable tie zip tie This moves it further from the heat of the exhaust pipe Mare sure that there is adequate free play in both the front lever and rear brake pedal Your Cobra Motorcycle has a 12 digit VIN Vehicle Identification Number The first four digits indicate the model and the nineth indicates the model year MY The exception is that 03 MY DC65 which came out late so the model year is off by one b Example DC65
32. o be welded as possible A WARNING Be sure the fuel tank and carburetor have been removed and safely located away from the welding process 2 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 M1 Replacing Transmission Lubricant Tools needed 530 ml 18 oz 85W 90 gear lubricant e large flat blade screwdriver 13 mm wrench or socket 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 runny but not so hot that there is risk of being burned by the engine or the oil A WARNING Hot oil and hot components on the motorcycle may cause burns 2 Lean bike against something or set on stand with oil drain hole 3 Using the 13 mm wrench remove the oil drain bolt located on the right side of the engine figure 1 Figure 1 4 After it has drained reinstall the drain screw with gasket 5 Remove the oil fill plug and pour in 530 ml 18 oz 85W 90 gear lubricant NOTE Leaning the bike over onto it s left hand side will facilitate the oil filling procedure 6 the oil fill screw securely being sure the gasket is in place 14 M2 Chain adjustment Tools needed e Two 19 mm wrenches or sockets 13 mm wrench or socket
33. oil type and level as well as compression and rebound damping you should adjust based on symptoms of incorrect suspension discussed in the next section 53 Symptoms of Incorrect Suspension Adjustment Front Forks Bottoming Too Frequently Fork oil level If the front forks bottom harshly more than a couple of times per lap and the fork springs are proper for the weight of rider as detailed above try raising the fork oil level in increments of 10mm Raising the fork oil level reduces the air volume and increases the stiffness of the forks late in the travel thus adding a progressive feel Front forks feel too stiff over small bumps Fork oil weight If the forks feel too stiff over small bumps try decreasing the weight increasing the viscosity of the fork oil Rear suspension troubleshooting Damping Always start with standard settings and make damping changes in no more than two click increments and only make one change at a time 40 Softer compression damping Bike tends to jump rear end low Softer rebound damping Frequent rear end bottoming Bottoms after end of continuous bumps Softer rebound damping Rear end kicks over square edge bumps 1 Harder rebound 2 Softer Compression ee S4 Proactive Suspension Adjustments Once you have the suspension adjusted for decent overall feel you can make proactive adjustments when faced with different racing conditions Acios Sand
34. t the Suspension oe nette xen bte cet 42 6 Suspension 43 ETE 44 E 45 General Information Specifications General Dimensions Wheelbase Wheel size Seat height Engine Type Cooling system Displacement Bore and stroke Ignition system Spark plug Fuel type Oil type Fuel oil mix ratios Ignition timing Carburetion Main jet Slow Pilot jet Transmission Speed Clutch Final drive ratio Jet needle Float height Transmission clutch oil type Quantity 44 75 1136 mm 14 356 mm front 12 305 mm rear 2 stroke single cylinder reed valve Liquid cooled 64 8 cc 3 95 Cubic inches 43 mm x 44 6 mm Electronic Splitfire SF406B 0 023 0 025 0 58 0 64 mm Sunoco 2 or 93 octane pump gasoline OTHER RACE FUELS ARE NOT RECOMMENDED Cobra Venom 2 cycle Race Oil 32 1 to 40 1 0 050 28 mm PWK style 128 38 JJH 3 position from the top 19 mm 0 5mm 0 75 0 020 Six speed Manual hydraulic 13 46 T 85W 90 Gear Lubricant 530 ml 18 oz Chassis Front tire 60 100 x 14 Pressure 10 15 psi Rear tire 80 100 x 12 Pressure 10 15 psi Front fork Cobra USD 35 mm Fork oil type SAE 5 weight Fork oil amount 4oz 118 ml Fork oil level Specifications Torque Va
35. tall the shock 2 Rebalance the bike by readjusting the front fork height 2 1 Loosen the fork triple clamps 2 2 Slide the forks up or down until the rear frame spars are vertical see figure13 and notes below 2 3 Tighten the front fork clamps 6 ft lb 8 Nm NOTE Measuring how vertical the frame spar is can be most accurately done by placing the motorcycle on a level surface and attaching a magnetic protractor to the frame spars Make the measurement while the bike is off the stand and with no rider onboard NOTE This measurement only needs to be approximately close to vertical at this point as some suspension setting to be made later will effect the precise value of this measurement Figure 13 37 STEP 3 Proper Race Sag Tools required Measuring tape Shock preload spanner Calculator or the ability to subtract without one NOTE Always be consistent with measuring units Stick with inches or millimeters mm Adjustment Procedure 1 Place the bike on a suitable stand to suspend the rear wheel off the ground 2 Measure the distance between the centers of the rear fender bolt and the rear axel bolt see figure 14 Write this number in table 1 as the Free Length Remove the bike from the stand and with your rider sitting aboard the bike record this measurement again and record it in Table 1 as the Race Length Bu NOTE Have the rider bounce on the seat a couple of times to overcome any static
36. the slide 10 Make note of what groove the clip is in on the end of the needle groove one is at the top and groove 5 is furthest away from the top 11 To adjust richer move the clip further from the top to a higher number and conversely to adjust the bike leaner move the clip closer to the top NOTE Make adjustment by one step at a time NOTE The clip can be easily removed and reinstalled by pressing the needle with the clip in position against the top of a table 33 Tuning 2 Suspension Topics included are Suspension Guidelines Proper Suspension Adjustments for Your Rider Symptoms of Incorrect Suspension Adjustment Proactive Suspension Adjustments How to Adjust the Suspension Suspension Reference Factory Track 1 Track 2 Track 3 Track 4 Viscosit amount 118 ml ON oom Preload height Rebound Damping clicks mE from full damp Compression Damping clicks from full damp m 10 34 51 Suspension Guidelines Proper suspension adjustment is a crucial component for a winning combination of rider and machine As important as the rider s abilities health and fitness or the performance of the engine the suspension controls what the rider feels and how the engine s power is delivered to the ground A good rider will struggle on a poorly suspended machine and a lesser rider will shine on a machine that is properly adjusted for his or her abilities physical stature and t
37. tween the centers of the rear fender bolt and the rear axel bolt with the bike off the stand but this time without a rider NOTE Bounce the seat a couple of times by hand to overcome any static friction stiction forces 39 2 Record the measurement in table 1 as the Load Length 3 Calculate the No Load Sag by subtracting the No Load Length from the Free Length and record it in the table 4 The target 19 mm 6mm 3 4 1 2 5 If your calculated No Load Length is not within this value you need to replace the spring and start at Step 2 5 1 If your value is greater than 25 mm 1 0 then you need a softer spring NOTE This may be counter intuitive It is because your current spring rate is sufficiently stiff that very little preload distance is required to get the proper Race Sag that is not enough distance for the spring to return it to full stroke 5 2 If your value is less than 13 mm 1 2 then you need a stronger spring NOTE This may be counter intuitive It is because your current spring rate is sufficiently soft that it requires so much preload to get the proper Race Sag that there is not enough loading of the bike itself to cause enough sag in the suspension 6 If your No Load Sag is acceptable then verify the following 6 1 Ride height is still acceptable if not readjust 6 2 Front to back balance is still acceptable Step 1 vertical frame spar if not readjust Other parameters such as Fork
38. uildup ii Has large dent in it e Compression is low i Piston ii Rings f Reeds are damaged g Ignition timing is incorrect Engine is excessively loud a Silencer needs repacking Engine blubbers at high RPMs a Jetting too rich Engine won t start a Fuel i None in tank ii 15 sour or bad b Carburetor is dirty C Ignition i Spark plug fouled i Spark plug cap off Engine Shut off kill switch is shorted iv Bad electrical ground v Stator winding damaged d Exhaust is plugged Engine won t idle a Idle knob needs adjusted b Carburetor jets are dirty 44 Index Air Filter 18 Bottom End DEVICE 20 Break h 10 Carburetion Specifications 5 Carburetor 27 Chain Adjustment 15 Chassis 5 TORGQUOG ts Su 7 Clutch PariS nanus bise anhand 21 DEI VICE sack 21 Clutch Lubricant Replacing 14 Engine 20 Specifications 5 6 Debita 26 Fork Replacement 19 Front Brake Adjustment
39. your carburetor jetting NOTE Make sure you change or clean your filter after each moto We recommend carrying three or more filters in your toolbox 18 1 for practice e 1 for each moto CAUTION It is recommended to apply medium strength blue thread locking agent to the threads of the air box side fasteners as well as the number plate fastener M7 Fork Oil Replacement Tools required Two 19 mm sockets or wrenches e 4 amp 5 hex key Allen wrench 10mm wrench 1 wrench or socket NOTE It is strongly recommended that you leave the front brake caliper attached to the fork leg for this procedure The mounting bolts are all that hold the two halves of the caliper together and disassembly would require bleeding the brake system Disassembly 1 Remove the front wheel 19 mm wrenches 2 Remove the front brake lever perch from the handlebars 4 mm hex 3 Remove the fork legs from the triple clamps 5mm hex key 4 Perform the following on one leg at a time Assembly Remove the fork cap 1 wrench Turn upside down over a suitable pan and allow to drain Work the fork in and out several times Allow to drain at least 15 minutes Fill the leg with 118 ml 4 Oz 5 wt fork oil 1 Measure the fork oil level to the top of the fork tube with the leg collapsed and record for tuning purposes 2 Install the fork spring 3 Reconnect the damper rod to the fork cap 12 ft lb 16 Nm Cie ee CAUT
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