Scorpion Super Stinger
Contents
1. Filter screen 3 Surge chamber 2 Vapor return line fitting irri Inlet fitting 1 COLOR CODE udin Fuel M Air Crankcase Impulse Air zT Fuel Vapor 2 3 SERVICE MANUAL 1975 SCORPION SUPER STINGER IDLE OPERATION see Fig 2 2 At idle speed the fuel passes from the idle take off 11 to the idle pocket 13 where it mixes with air from the secondary idle holes 16 This rich mixture passes around idle needle 12 through the idle discharge port 14 where it mixes with ad ditional air passing the throttle valve 19 at point 15 FIG 2 2 IDLE OPERATION MU Power needle 2 4 i Choke valve i Throttle valve closed 19 aa 22 3 i WV Ly Main fuel nozzle x Hi IF Part throttle holes i ze Secondary idle holes 16 li I E Point 18 WE Idle discharge port 14 Vapor and fuel 77222 gu wb ox of Idle poit 13 return 2 il A idle needle Needle valve lt lt 2 zi EV 2 S i Idle take off 11 aN f acra mam i S Impulse fitting Secondary NS wd iw E eA 4 Fuel pump diaphragm 4 7 a j pum ime J LESE 2 lt ilter screen re i as Vapor return line fitting l f MI Inlet fitting dd ab COLOR CODE Vapor return Fuel inlet E Fuel E Air Crankcase Impulse Air 55 Fuel Vapor SERVICE MANUAL 1975 SCORPION SUPER2. If there is a sufficiently heavy load on the magneto during the first half cycle the load effectively holds the voltage output to a value less than that required to turn the SCR on and therefore full output goes to the load 2 5 REGULATOR CONNECTOR FIG 3 14 MAGNETO VOLTAGE REGULATOR SOLID STATE P N 043299 3 7 SERVICE MANUAL 1975 SCORPION SUPER STINGER ELECTRICAL CONTROL AND DISTRIBUTION Functional Description Power is supplied continuously to the tachometer mechanism and to the brake light switch so that any time power is being generated the tachometer will indicate and the brake light will go on if the brake is applied Power to all the other items is supplied through the ignition switch in the LIGHTS mode Grounding of the System is accomplished at three locations l Tothe chassis at the rear end 2 Tothe instrument panel 3 Tothe stator plate on the engine MAIN ELEMENTS Main Wiring Harness Seat Wiring Harness Taillight Wiring Harness Safety Stop Switch Break Light Switch Hi Lo Switch Ignition Switch 3 8 3 15 3 16 6 8 SAFETY STOP SWITCH TACHOMETER am MOVEMENT TACHOMETER amp PEEDOMETER 0000005 Ea S LIGHTING LIGHTS COILS IGNITION COIL i 00 E IGNITIO LIGHT i i m SWITCH Tf SWITCH z gt Q x en m lt 4 m gt 2 c m a pee BEI gt ET
3. Repair or replace wires Adjust clean or install new points Replace coil or condenser Refuel using specified fuel oil mixture Replace seal Clean adjust or install new plugs Repair or replace wires Clean adjust or install new points Replace coil or condenser Install specified spark plugs Replace head gasket Re time engine SERVICE MANUAL 1975 SCORPION SUPER STINGER TROUBLE SHOOTING CHART TROUBLE PROBABLE CAUSE REMEDY Coughs spits slows 1 Idle or high speed jets too to 5 down surges lean Adjust carburetor or fuel 2 Leaking gasket flange pump Refer to Carburetor 3 Inlet control level set too Section low 4 Pulsation line obstructed 5 Fuel pump not supplying enough fuel due to 1 Punctured diaphragm 2 Inoperative flapper valve 6 Crankcase not properly 6 Reseal crankcase sealed 7 Idle or main carburetor 7 Refer to Carburetor nozzle obstructed Section 8 Fuel line obstructed 8 Remove fuel line Clear obstruction Replace line 9 Carburetor inlet needle and 9 Refer to Carburetor seat obstructed Section 10 Welch plug leaking 10 Refer to Carburetor Section Overheating 1 Carburetor too lean 1 and 2 Adjust carburetor 2 Carburetor too rich Refer to Carburetor Section 3 Incorrect timing 3 Retime engine to Specifica tions 4 Too much carbon 4 Remove cylinder heads Clean top of pistons and inside compres
4. Fig 1 57 c Remove tool from vise Grasp the tool by its handle and lower the tool with spring installed into case 1 Fig 1 58 d Secure the long rolled end of spring over the fixed spring retaining pin Fig 1 59 Remove winding tool Fig 1 60 Apply a light film of Lubriplate or equivalent to spring 3 Secure case open side up in bench vise 4 Tie a knot at one end of the rope Secure knotted end in the center of reel 2 Pull rope taut and wind entire rope around reel in an anti clockwise direction until the free end protrudes through the notched section of the reel 5 Apply a light film of Lubriplate or equivalent to center hub of case and install the reel Push down and rotate reel in an anti clockwise direction until the hook en gages with the free end of main spring Ten sion will be felt when reel and spring are pro perly engaged Fig 1 61 1 62 6 Rotate reel a maximum of three complete turns in an anti clockwise direction Do not exceed three turns hold reel in this position and feed free end of rope through case at the rope guide hole Install rope guide Loosely knot the rope to prevent recoil 7 Apply a light film of Lubriplate or equivalent to pawls 6 and install them on the reel in the pawl retainers Fig 1 63 See Fig 1 49 for part identification numbers 8 Install cup washer 7 flat side down spring 6 and return spring Ensure that plain end of retur
5. 11 Re time engine to specifica tions SERVICE MANUAL 1975 SCORPION SUPER STINGER TROUBLE SHOOTING CHART TROUBLE Engine runs by using 1 choke at high speed No power under 1 heavy load PROBABLE CAUSE High speed needle set too lean Dirt behind needle and seat Fuel line obstructed Inoperative fuel pump Magneto breaker points improperly gapped or dirty Ignition timing too far advanced Magneto coil plate loose Faulty carburetion REMEDY amp 2 Adjust carburetor Refer to Carburetor Section Remove line clear obstruc tion replace line Refer to Carburetor Section Clean adjust or install new points Adjust timing Check magneto and secure coil plate Refer to Carburetor Section Cranks over 1 extremely easy 2 one or both cylinders 3 Loss of compression 4 Scored piston Blown head gasket Loose spark plug Head bolts not tight Replace faulty piston Replace head gasket Check plug for security Torque head bolts to proper specifications Engine won t crank l over Unable to rotate flywheel Piston rusted to cylinder wall Crankshaft seized to bearing main or rod Broken connecting rod Flywheel seized to coil plate Engine properly assem ed after repair gt Remove piston and cylinder Replace defective parts amp 3 Disassemble engine Replac
6. Heat the piston with a heat gun or propane torch Heat only to the point where piston may still be held in hand Push the pin out To separate the crankcase halves hold upper portion of crankcase assembly in one hand lifting slightly and tap the end of the crank case with a soft hammer The crankcase will separate and the crankcase may be removed See Fig 1 24 SERVICE MANUAL 1975 SCORPION SUPER STINGER Crankshaft Bearings To remove crankshaft end bearings use bearing puller 444 31 807 0 See Figs 1 25 1 26 1 27 Slip the puller half shells around the outer bearing race and around puller assembly Slide the retaining ring over the half shells Using two 2 27 mm wrenches turn the center bolt clockwise with one wrench and use the second wrench to hold the puller body Before removing the PTO side crankshaft bearing insert a 1 2 20 UNF bolt 1 2 long to protect the internal thread of the crankshaft FIG 1 25 FIG 1 26 FIG 1 27 SERVICE MANUAL 1975 SCORPION SUPER STINGER ASSEMBLY A Crankshaft Bearings Heat crankshaft bearings in oil or oven to approximately 180 degrees Slide bearing on crankshaft Crankcase Inspect and clean both halves of crankcase The proper sealant material such as Per matex Hy Tack Spray should be now sprayed on crankcase sealing surfaces See Fig 1 29 Before installing crankshaft into crankcase lower half of it will be necessary that all bearing
7. SNOWMOBILE SUSPEN SION TRACK TENSION Proper track tension is extremely important to assure long life of all associated com ponents and efficiency of the track drive system The track tension should be checked at the following intervals 1 When the machine is new dealer preparation 2 After the first 10 hours 3 Every 30 days or 200 miles of operation 4 Atthe start of each snow season The following procedure applies to all Para Rail Snowmobile Suspension equipped Scorpion snowmobiles 1 The track should be at room tem perature or should have been recently run to remove any stiffness caused by cold weather 2 Elevate the rear of the machine 3 Adjust each Track Jack to one and one quarter inch 1 4 Insert both Track Jacks between the track and both bogey wheels located on the third bogey axle ahead of the rear idler wheels 5 If the track is properly tensioned the green ring should be just visible or aligned with the lip of the cylinder Ad justment is required if the green ring is not visible or is above the lip of the cylinder 6 To make adjustment loosen the lock nuts on the track adjustment bolts as well as the rear suspension mounting screws rear of tunnel just below seat and either tighten or loosen the ad justment bolts until proper adjustment is measured on both Track Jacks green ring aligned with lip on cylinder 7 Retighten the lock nuts on the tr
8. Clean as required Reassemble in reverse sequence of disassembly 2 7 SERVICE MANUAL 1975 SCORPION SUPER STINGER MAIN CARBURETOR BODY DISASSEMBLY IN CONJUNCTION WITH INLET NEEDLE VALVE CIRCUIT PLATE METERING LEVER 1 Remove the four screws holding the SCREWS PIN SCREW plates to the main body and disassemble im BER C in one mass 2 Remove metering lever pin screw FIG 2 6 3 Remove metering lever Watch that spring does not fly out FIG 2 6 4 Remove spring and Inlet Needle Valve 5 Clean or replace as required METERING METERING LEVER LEVER MAIN CARBURETOR BODY DISASSEMBLY IN SPRING CONJUNCTION WITH FINAL CHECK VALVES AND DIAPHRAGMS FIG 2 6 1 It is not necessary to remove Inlet Needle Valve assembly but it may be easier to work in this area without them See CIRCUIT PLATE SUREEN Procedure Above 2 Remove three circuit plate screws FIG 2 6 3 Remove circuit plate check valve diaphragm and gasket FIG 2 7 4 Inspect check valve diaphragm 5 Remove Low and High speed needles if necessary for cleaning grooves channels etc NOTE DO NOT REMOVE SCREEN UNDER HIGH SPEED NEEDLE CAR BURETOR WILL NOT FUNCTION WITH SCREEN REMOVED See FIG 2 7 CHECK VALVE FIG 2 7 DIAPHRAGM amp GASKET 2 8 SERVICE MANUAL 1975 SCORPION SUPER STINGER LOW SPEED ADJUSTMENT 400 amp 440 SUPER STINGER On 400 and 440 Super Stingers equipped with throttle cra
9. Fig 1 16 Remove fan housing from crankcase See Fig 1 17 FIG 1 16 Unplug connector housing coil wires Note color coding of wires Remove armature plate assembly and wires as a unit from fan housing SERVICE MANUAL 1975 SCORPION SUPER STINGER Remove the fan by tapping the end of fan shaft with a soft hammer With a flat punch and hammer tap the inner race of the fur thest bearing in the housing See Figs 1 18 1 19 1 20 FIG 1 19 G Remove spark plugs with spark plug wrench See Fig 1 21 H Cylinder Heads Remove cylinder head nuts with a 13 mm socket wrench Mark cylinder heads before removal from cylinder Remove and discard gaskets See Fig 1 22 l Cylinders FIG 1 21 Remove the eight 8 cylinder base nuts using a 13 mm socket wrench and remove the eight 8 spring washers The cylinders may be removed See Fig 1 23 NOTE IMPORTANT If removal of cylinders only is required care must be taken that the crankcase seal is not disturbed The removal of the PTO cylinder will allow the placement of two bolts and nuts with flat washers to apply constant pres sure to crankcase assembly Bolts should be placed in the center two holes adjacent to the fan side cylinder See Fig 1 31 The second cylinder may now be removed FIG 1 23 SERVICE MANUAL 1975 SCORPION SUPER STINGER Piston and Wrist Pin With needle nose pliers remove circlips from pistons
10. HI LO TAILLIGHTS SWITCH e BRAKE LIGHT 3 2 e VOLTAGE WIRING SCHEMATIC COLOR CODED REGULATOR ELECTRICAL DISTRIBUTION amp CONTROL 1975 SUPER STINGER 4 2 a m SERVICE MANUAL 1975 SCORPION SUPER STINGER WIRING CODE ELECTRICAL DISTRIBUTION amp CONTROL YELLOW RED YELLOW BLACK RED TAN YELLOW GREEN BLUE WHITE ORANGE ORANGE BLACK GROUND HOT GROUND HOT HOT HOT HOT HOT HI HOT LO HOT GROUND ENGINE CONNECTOR ENGINE CONNECTOR VOLTAGE REGULATOR BRAKE LIGHT SWITCH IGNITION SWITCH IGNITION SWITCH HI LO SWITCH HI LO SWITCH ENGINE CONNECTOR ENGINE CONNECTOR RECOMMENDED TOOLS FOR SERVICING 1 Standard Screwdriver 4 blade 2 Phillip s Screwdriver 3 7 16 open end Wrench 4 See Engine Section for removing amp installing stator 3 10 REGULATOR REGULATOR BRAKE SWITCH CONN IGNITION SWITCH BRAKE LIGHT HI LO SWITCH TAILLIGHT SPEEDOMETER LIGHT TACHOMETER LIGHT ELECTRIC START HEADLIGHT HEADLIGHT TACHOMETER TACHOMETER SERVICE MANUAL 1975 SCORPION SUPER STINGER SPECIAL TESTING ELECTRICAL Regulator Tests 1 Resistance across Regulator P N 042748 Hook ohmmeter across regulator leads Resistance should read between 100 and 1000 ohms If resistance is less than 100 the SCR is shorted If the resistance is above 1000 generally the lamp has burned out opening the circuit See FIG 3 12 2 Set point check P N 042748
11. Lbs 21 15 19 Ft Lbs 22 15 19 Ft Lbs 25 15 19 Ft Lbs 53 15 19 Ft Lbs 54 15 19 Ft Lbs 5 9 SERVICE MANUAL 1975 SCORPION SUPER STINGER SPECIAL ADJUSTMENTS PARA RAIL SNOWMOBILE SUSPENSION ADJUSTMENT The rear spring adjustment governs preload and should be correlated with the weight of the rider or riders normally using the machine Too much spring tension will result in a harsh ride and increases the weight carried on the skis thus increasing steering effort Too little spring tension will result in the bot toming out of the suspension a harsh ride and shortened life to the suspension components will occur 1 The proper spring tension may be obtained by having the rider s sit on the machine in the normal sitting position and measure the distance between the floor and the bottom of the running board at the rear of the machine either side This measurement must be 4 to6 2 To adjust loosen the nuts on the eye bolts and adjust accordingly making certain that each spring is tightened or loosened the same amount 3 Repeat Step 1 and tighten the nuts on the eye bolts securely when the 4 to 6 measurement is attained NOTE When 300 lbs combined passenger weight is normally carried on machine a heavy duty spring kit should be installed on machine This kit is available at your Scorpion istributor as an accessory item 5 10 SERVICE MANUAL 1975 SCORPION SUPER STINGER PARA RAIL
12. STINGER PART THROTTLE OPERATION see Fig 2 3 At part throttle in addition to the fuel fed into the throttle bore by the idle system more fuel enters past the check valve 32 through passage 26 around the power needle 22 and through the passage 18 and discharged into the throttle bore 20 through the part throttle holes 17 All ports except the main nozzle feed progressively as throttle valve opens for smooth ac celeration Air is intermixed through air bleed nozzle 25 FIG 2 3 PART THROTTLE OPERATION Power needle Venturi 23 F Throttle valve Choke valve 24 Main nozzle Throttle bore Part throttle holes Secondary idle holes Air bleed nozzle 25 Passage E Idle needle Needle m 7 a Fh Passage c Fuel pump diaphragm lS SN beer Vapor return line fitting 38 Inlet fitting 1 to fuel tank i i VU 22 19 21 20 17 16 14 18 12 26 32 9 4 2 5 SERVICE MANUAL 1975 SCORPION SUPER STINGER FULL THROTTLE OPERATION see Fig 2 4 Note Starting idle and part throttle operations of the WDA carburetor are identical to that of the WD and WR models You will notice the main difference is the discharge of fuel at full throttle operation The WR discharges fuel through 21 main nozzle at only the base of the power needle where as the WD and WDA discharge at five discharge ports parallel to powe
13. actuates the carburetor fuel pump diaphragm to move the fuel into the carburetor from the fuel lines An increased engine fuel demand causes a reduced pressure at the metering diaphragm which opens the needle valve More fuel enters through the needle valve into the carburetor bore where it is mixed with in coming air The four operational phases of the Walbro Carburetor used on the 1975 Super Stinger are 1 Starting choke operation 2 Idle operation 3 Part throttle operation 4 Full throttle operation Detailed performance of the carburetor in each of the four phases is described below Figures 2 1 through 2 4 are schematic diagrams and as such are accurate functional representations of the carburetor but in some features deviate from actual physical appearance 2 2 SERVICE MANUAL 1975 SCORPION SUPER STINGER STARTING CHOKE OPERATION See Fig 2 1 Fuel from the supply tank is drawn in the fuel inlet 1 into the surge chamber 2 through the filter screen 3 by pulsations of the fuel pump diaphragm 4 The engine crankcase pulsation transmitted through the external impulse fitting 9 or internal impulse hole 9A actuates the fuel pump diaphragm 4 which supplies pumping action for the fuel pump The fuel is drawn from the surge chamber through the check valve 5 and the channel 6 The fuel continues past the fuel pump outlet check valve 7 and into channel 8 Fuel continues through fuel channel 8 and to the need
14. leaks The test procedure is as follows 1 Disconnect the fuel line from the fuel in let connector on the carburetor 2 Connect the leak detector Scorpion P N 907000 pressure line to the carburetor fuel inlet connector 3 Remove the carburetor vapor return line and hold your finger over the carburetor fitting 4 Pressurize the carburetor with the leak detector plunger pump Do not exceed 12 PSI The needle valve properly seated should hold a constant 8 psi SERVICE MANUAL 1975 SCORPION SUPER STINGER 2 12 SERVICE MANUAL 1975 SCORPION SUPER STINGER TROUBLE SHOOTING CHART TROUBLE Excessive carbon build up in engine amp on spark plugs or engine flooding Fuel Rich Condition PROBABLE CAUSE Foreign obstacle under inlet needle Diaphragm lever adjust ment OFF Metering lever spring not seated in dimple on metering lever Leaking fuel pump diaphragm Foreign matter under umbrella check valve Wrong angle or abused metering portion of high speed needle Leaking check valve in primer REMEDY Remove needle valve Inspect and clean See Procedure P 2 8 See Fig 2 13 Should be 020 above surface of valve body Remove plates and inspect spring Locate spring correctly See FIG 2 6 Install new diaphragm Blow through screen on opposite side of Plate 413 See FIG 2 5 Umbrella check valve is orange c
15. operating diameter of the drive and driven clutch governs the ratio of reduction or ad vantage in the snowmobile drive train Therefore to gain maximum performance and economy these areas cannot be overlooked The following are some symptoms causes and cures to aid in trouble shooting the clutch drive system TROUBLE CAUSE Drive clutch may not be closing fully This can be checked by drawing a line on the face of the sheave drive or driven with a crayon from the center outward Then running the machine at top speed will tell you how far the clutch closed by erasure of the line by the belt Engine Overspeed If the clutch is closing fully the belt may be wrong length or the center to center distance of the clutches may be off Finally check the number of teeth on upper and lower sprockets Tachometer may be reading incorrectly high Belt may be worn and too narrow to achieve correct ratio see belt specs Excessive Track may be too loose allowing sprockets to vibration of slip over drive lugs or ratchet drive train Chain may be slipping over teeth on sprockets Excessive noise Malfunction of front drive bearings from front drive system Chain case may be dry of oil 4 16 REMEDY Disassemble clutches examine and replace malfunctioning parts Replace belt Correct center to center dis tance see belt specs Replace incorrect sprocket Replace tach Replace belt Correct track tens
16. outer surfaces be wiped clean of foreign material so that proper sealing will occur After installing PTO thrust washer and oil seal inside groove of oil seal coated with light grease place the crankshaft carefully into the lower crankcase half and properly position all components See Figs 1 30 Placement of the upper crankcase half may now be made Be certain that the center seal is lined up with the crankcase split line Tap upper crankcase half to seat with lower half BEARING FIG 1 28 SEAL BEARI NG FIG 1 29 FIG 1 30 SERVICE MANUAL 1975 SCORPION SUPER STINGER Install two crankcase holding bolts in the center holes of the PTO side of crankcase Fig 1 31 Tighten finger tight CIRCLIP OPENING HERE Piston Cylinder and Cylinder Heads The pistons must be clean and free from car bon deposits and the piston rings must fit freely in their grooves Rings are marked for proper side up The arrow on the crown of pistons must point toward exhaust side of engine Piston pins needle bearings check plates and circlips may now be installed ac cording to the procedure below Always use new circlips See Figs 1 32 1 33 1 34 1 35 FIG 1 33 E T he T F d ne mm a J FIG 1 31 E FIG 1 32 SERVICE MANUAL 1975 SCORPION SUPER STINGER Oil the piston pin end bearings Install one circlip in piston Heat the piston sufficiently to a
17. 043299 Use test circuit as shown below Read voltage across regulator Value should be approximately 13 8 volts 100W 120V REGULATOR SET POINT TEST CIRCUIT 3 11 SERVICE MANUAL 1975 SCORPION SUPER STINGER TROUBLE No lights Dim lights Burned out lights all Burned out lights individual Burned out lights Engine won t run Weak or no spark Engine won t run Adequate spark Unacceptable Engine Performance 3 12 PROBABLE CAUSE Open Circuit Faulty Switch s Separated Connector s Cut Wiring Wiring shorted to ground Damaged Insulation Faulty Regulator Shorted SCR Shorted or open lighting coil Faulty regulator Incorrect regulator set point too low Faulty regulator burned out regulator light bulb Incorrect Set Point too high Failed bulb Intermittent short in wire harness Open or shorted windings in ignition coils stator Open or shorted windings in external ignition coil Shorted condensor dirty or worn Damaged burned points Burned or fouled plugs See Engine Trouble Shooting Section See Engine Trouble Shooting Section TROUBLE SHOOTING ELECTRICAL REMEDY Repair or replace faulty or damaged element Repair or replace damaged or faulty element Replace regulator Replace armature plate Replace regulator Replace regulator and failed bulbs Replace bulb Repair or replace wire harness 1 R
18. 1975 Scorpion Super Stinger Service Manual Engine Section SERVICE MANUAL 1975 SCORPION SUPER STINGER ENGINE SYSTEM Functional Description 2 CYCLE ENGINE FUNDAMENTALS The Rockwell 2 cycle air cooled gasoline engine particularly the axial fan cooled twin cylinder engine has become very popular today for snowmobiles It is uniquely qualified for this ap plication because of its high power output light weight and ease of lubrication with fewer moving parts than other conventional 2 cycle and 4 cycle engines However in order to get the best possible use and ensure that it retains its high degree of dependability and endurance it must receive proper care and maintenance Therefore it is necessary for us to know something about the basic fundamentals of this engine and how it functions OPERATION The Rockwell 2 cycle Twin Cylinder engine is of the loop scavenged third port type the most widely used design today It uses a mixture of gasoline oil and air for combustion lubrication and cooling It fires on every stroke of each piston There are two power strokes for every revolution of the crankshaft As the piston moves upward in the cylinder it draws the fuel air mixture into the crankcase through the intake manifold while at the same time compressing fuel that has been forced into the combustion chamber See Fig 1 1A TRANSFER As the piston nears top dead center the spark plug is fired and the com
19. 4 No 1 cylinder terminal in connector housing See Fig 1 65 C Rotate flywheel counterclockwise until points are on the high side of cam on No 1 cylinder Points are at maximum open posi tion observed through opening in flywheel Check gap with wire gauge and adjust to 015 if necessary See Fig 1 66 FIG 1 66 1 30 D SERVICE MANUAL 1975 SCORPION SUPER STINGER Lata we Rotate flywheel counterclockwise to top dead center and adjust dial to zero Place selector knob on ohmmeter to R x 1 Ohm meter needle will indicate a closed circuit See Fig 1 67 Move the centrifugal weights in flywheel to the full advanced position See Fig 1 68 Rotate flywheel counterclockwise one com plete revolution to between 102 and 112 See Fig 1 69 FIG 1 69 1 31 SERVICE MANUAL 1975 SCORPION SUPER STINGER At this point the breaker points for No 1 cylinder should open Break contact This will show on the ohmmeter Needle will move to the left If this does not occur the ar mature plate needs adjusting This is ac complished by loosening the hold down screws and turning plate either left or right while observing needle action With proper positioning needle should move to left with slight movement of armature plate and flicker back with opposite plate movement Tighten hold down screws securely Re check procedure See Fig 1 70 NOTE In Fig 1 70 flywheel has been removed for clarity of illustra
20. GNITION COIL STATOR RERRRRRRA CONDENSER CONDENSER aH Hr ze v SPARK PLUG POINTS 009000004 EXTERNAL IGNITION COILS SPARK PLUG si i pem FIG 3 8 IGNITION SCHEMATIC ENGINE CONNECTOR 3 4 SERVICE MANUAL 1975 SCORPION SUPER STINGER STATOR IGNITION COIL TO EXTERNAL COIL CONNECTORS Ta Z FIG 3 9 EXTERNAL COIL COIL TO SPARK PLUG LEAD EXTERNAL COIL GROUND FIG 3 10 3 5 SERVICE MANUAL 1975 SCORPION SUPER STINGER VOLTAGE REGULATION Functional Description The voltage regulator is connected across the lighting coils in parallel with the electrical load of the sled See SCHEMATIC ELECTRICAL DISTRIBU TION AND CONTROL FIG 3 17 Under operating conditions the voltage drop across the regulator is such that approximately 13 8 V RMS is supplied to the snowmobile lighting circuit Two types of regulators are described in this section Scorpion P N 042748 See FlGs 3 11 3 12 and 3 13 MAIN ELEMENTS 1 Trimmed Resistor 2 Light Bulb 3 Photo Electric Cell 4 Diac Trigger 5 Silicon Control Rectifier Thermatab The intensity of the light output of the light bulb directly indicates the RMS Voltage level When the intensity exceeds a specific level a sequence of events occurs The light is sensed by the photo cell A signal from the photo cell actuates the diac The diac triggers the SCR The SCR conducts in effect short circuiting the lighting coil for part of the cycle
21. SUPER STINGER DRIVEN CLUTCH INSPECTION Inspect snap ring groove for wear Inspect Helical ramps for wear and breakage See Fig 4 13 Inspect bronze bushing in cam bottom for any signs of looseness or slippage should be staked in solidly Rotate and check bearings visually Inspect sheaves for cracks particularly around bolt holes Check splines and threads on sprocket side of main shaft for wear crossthreading etc RE ASSEMBLY OF DRIVEN CLUTCH Attach stationary sheave to clutch shaft Assem ble cam bottom and movable then place on shaft followed by the woodruff key and main spring Place cam top on shaft preloading spring turn and install washer and snap ring Upon replacing the driven clutch in chaincase check to assure that the O ring in chaincase bore is intact and in good condition Also check O ring in chaincase cover before installation 4 12 SERVICE MANUAL 1975 SCORPION SUPER STINGER DRIVE BELT SPECIFICATIONS Drive belt width Drive belt outside diameter inches 1 1 8 13 16 inches 43 1 8 43 1 4 Clutch offset Drive to Driven 3 8 inch Center to center distance 10 inches Drive clutch to Driven clutch DRIVE CLUTCH n CLUTCH ALIGNMENT BAR For 3 8 Offset DRIVEN CLUTCH FIG 4 20 SERVICE MANUAL 1975 SCORPION SUPER STINGER CHAINCASE DISASSEMBLY Remove cover tensioners upper and lower bolts Remove sprockets with chain Remove bearing flange bolts a
22. See FIG 3 11 This action regulates the RMS Voltage to the lighting circuit at the required level REGULATOR CONNECTOR 3 6 NORMAL LIGHTING COIL VOLTAGE ALTERATION OF VOLTAGE WAVE WHEN SCR CONDUCTS VOLTAGE TIME FIGURE 3 11 VOLTAGE REGULATOR FIG 3 12 P N 042748 043299 TRIMMED RESISTOR THERMATAB PHOTOCELL SCR TRIGGER DIAC FIG 3 13 VOLTAGE REGULATOR SCHEMATIC P N 042748 SERVICE MANUAL 1975 SCORPION SUPER STINGER Scorpion P N 043299 See FIGs 3 11 3 12 and 3 14 MAIN ELEMENTS 1 Silicon Control Rectifier SCR 2 Resistors R1 R2 R4 Trim 3 Condenser C1 4 Diodes CR1 CR2 CR3 CR4 5 Transistors Z1 Q1 This solid state regulator is also a shunt type regula tor When the magneto output drops below the specified pre set regulator voltage level the regula tor drops out of the system providing maximum available voltage to the load at decreased speeds In the first half of the operating cycle when line 1 is positive with respect to line 2 C1 will charge through C1 R2 and CR2 until the voltage drop across Cl reaches the level necessary to cause 21 to conduct At this point Q1 will draw base current and then pass current through CR1 the emitter col lector of Q1 and into the gate of SCR SCR is turned on and shunts the output of the magneto In the second half cycle the shunting mechanism of the regulator is not operative
23. ack ad justment bolts as well as the rear suspension mounting screws NOTE Track Jacks are available at Scor pion Inc It is an accessory item Part 901736 FIG 5 16 SERVICE MANUAL 1975 SCORPION SUPER STINGER IN THE EVENT Track Jacks are not available the following procedure may be employed to achieve track tension The track should be at room temperature or should have been recently run to remove any stiffness caused by cold weather Elevate the rear of the machine 3 Apply ten 10 lbs of force or weight evenly distributed across the track under both bogey wheels located on the third bogey axle ahead of the rear idler wheels 4 To make adjustment loosen the lock nuts on the track adjustment bolts as well as the rear suspension mounting screws rear of tunnel just below seat and either tighten or loosen the adjustment bolts to achieve the 14 inch clearance between track and bogey wheels 5 Remove ten 10 lbs force or weight and retighten the lock nuts on the track ad justment bolts as well as the rear suspen sion mounting screws 5 12
24. ating a permanently magnetized flywheel about the ignition coil The current initiated in this coil in turn energizes the primary coils of the external ignition coils The secondary coils of the external ignition coils are situated in the force field generated by the primary coils When the points close causing an interruption of the current flow through the primary winding its force field immediately collapses and generates a very high voltage in the second coil This voltage in the region of several thousand volts will jump the spark plug gap causing ignition to begin The collapsing lines of force cut through the primary windings raising the voltage in that circuit also As this occurs the condenser absorbs the gene rated current to reduce the tendency to overload the points As soon as the voltage level in the primary winding drops below that of the condenser current again flows in the original direction energizing the system This occurrence and the re versal happens several times each cycle creating a powerful long duration spark for more reliable ignition gt MAIN ELEMENTS Ignition Coil Stator Condensers 2 Breaker Points 2 ignition Coils External 2 Spark Plugs 2 DI e sal STATOR FIG 3 6 3 3 SERVICE MANUAL 1975 SCORPION SUPER STINGER SEE ENGINE DISASSEMBLY POM IGNITION COIL STATOR SECTION 1 FOR FLYWHEEL 3 wi AND STATOR REMOVAL E M 5 r1 CONDENSERS FIG 3 7 I
25. cker carburetor use the following sequence for low speed adjustment Make sure throttle cracker screw is secured tightly in choke shaft Back off idle speed screw so it does not con tact throttle arm Turn idle speed screw in until contact is just made with throttle arm Turn idle speed screw in one full turn Turn Low Speed Mixture screw until needle seats lightly Back off one turn Close choke and start engine prime if necessary Engine will run with choke closed Do not use throttle in starting or engine will immediately flood 8 Open choke and let engine warm up 9 Turn idle mixture screw reach maximum R P M on Tach Continue turning until R P M start to drop 10 Screw idle mixture screw ouf to reach maximum R P M Continue out until R P M drop 11 Set idle mixture screw half way between drop points This is the correct idle mixture setting 12 Adjust idle speed screw to obtain 2 200 R P M LOW SPEED ADJUSTMENT 290 AND 340 SUPER STINGER 290 and 340 engines do not have a throttle cracker carburetor For low speed adjustments follow Steps 9 through 12 of LOW SPEED AD JUSTMENT 400 and 440 SUPER STINGER IDLE SPEED SCREW THROTTLE FIG 2 10 CRACKER SCREW LOW SPEED MIXTURE SCREW FIG 2 11 SERVICE MANUAL 1975 SCORPION SUPER STINGER CARBURETOR PRESSURE TEST WRA and WDA CARBURETORS The pressure test is used to determine if the needle valve
26. ds See Fig 1 40 NOTE The head gasket for the 400 cc engine has an additional hole in it to dis tinquish it from the 440 cc gasket FIG 1 39 FIG 1 40 1 21 SERVICE MANUAL 1975 SCORPION SUPER STINGER D Fan Housing and Impeller Bearings Clean fan shaft hub Install circlips and spacer Use grease to hold spacer in place O RING SEAL Pack bearings in medium grease into housing with sealed surface outward See Figs 1 19 1 20 Install fan and shaft E Fan Housing and Armature Plate Install new seal in fan housing Lubricate the inner groove of the oil seal with a light grease See Fig 1 41 Install new o ring and apply sealant material around o ring surface see Fig 1 41 Install the armature plate wires through hole in fan housing and install armature plate with hold 9 down screws washers and lockwashers See Fig 1 42 Place fan housing assembly over crankshaft and position to crankcase assembly Install FIG 1 41 the four Allen head screws and lockwashers and tighten evenly until fan housing is against crankcase assembly See Fig 1 43 FIG 1 42 FIG 1 43 1 22 SERVICE MANUAL 1975 SCORPION SUPER STINGER Torque to sixteen 16 to eighteen 18 foot pounds Connect ignition wires to external ignition coil and to connector housing Check ground wires for proper position install ignition cable bracket to fan housing Intake Manifold Install
27. e defective parts Remove flywheel Replace defective parts Recheck re assembly procedure 1 37 SERVICE MANUAL 1975 SCORPION SUPER STINGER The following are possible causes of piston failures on Rockwell 5 and 8 engines 5 is 1973 version The 8 is the 1974 and 1975 version 1 38 Insufficient break in period before full throttle application High speed needle adjusted too lean especially on 8 400 engines Baffle foam caught in carburetor flange causing air leak Leaking air silencer boots on early production models Pick up in fuel tank too long Loose carburetor on intake manifold causing air leak Leaking crankcase halves Leaking crankcase seals Leaking impulse fitting or plug Intake manifold spacers cracked causing air leak 8 engine Intake manifold misaligned 5 engine Leaking cylinder head gaskets Screen in 1973 5 engine carburetors not removed Leaking primer pumps Drive clutch weight bushings ticking causing over revving of engine Substandard fuel Excessive compression 1975 Scorpion Super Stinger Service Manual Carburetor Section SERVICE MANUAL 1975 SCORPION SUPER STINGER Functional Description General The purposes of the carburetor are 1 to provide the amount of fuel that the engine needs in operation and 2 to properly mix the fuel with air so that it will vaporize Pulsations from the crankcase through the impulse tube
28. ectric starter 4 Check starter solenoid 5 Inspect starter motor for evidence of moisture and broken or worn brushes Dry out as necessary Check starter switch Replace if required Check harness or connector for broken wire Repoir or re place nnn aaaa Hard start or won t start 10 a A Q Carburetor adjustments too lean not allowing enough gas to engine Inoperative diaphragm or flapper valve Engine not being choked to start Spark plugs improperly gapped dirty or broken Magneto breaker points improperly gapped or dirty Head gasket blown or leaking Empty gas tank or improper fuel mixture Water in fuel system Weak coil or condenser Obstructed fuel system o N Adjust carburetor Refer to Carburetor Section Refer to Carburetor Section Ensure choke is fully closed Remove plugs Clean adjust or install new plugs Clean adjust or replace points Replace gasket Refill tank with specified fuel oil mixture Drain fuel from carburetor Add carburetor de icer as re quired to fuel Replace faulty coil or condenser Disconnect fuel lines clear obstruction Flush system Connect fuel lines 1 33 SERVICE MANUAL 1975 SCORPION SUPER STINGER TROUBLE SHOOTING CHART conr TROUBLE impossible to adjust idle Missing at low speed or won t idle smoothly or slow
29. ed open against the helical cam This action winds up and compresses the spring Under steady running all forces are balanced and the belt chooses a ratio at which this balance exists Under deceleration the driven sheave is stalled slightly which unbalances the forces so that the sheave is forced to a new larger pitch diameter Belt tension is thus increased the wedging action opens drive sheave and a new lower pitch diameter is chosen to again bring all forces to balance 4 2 SERVICE MANUAL 1975 SCORPION SUPER STINGER DRIVE CLUTCH DISASSEMBLY 1 Remove engine cover disconnecting choke amp primer Remove clutch guard See Figure 4 1 2 Remove clutch attaching bolt and bell retaining bolt Use impact wrench capable of 75 or more ft Ibs torque In the field alter nate method may be used Making sure ignition is off run engine up on compression using 4 socket and ratchet Strike ratchet VER plastic or rubber mallet See Figure 4 2 3 Remove bell housing See Figure 4 3 FIG 4 3 4 3 SERVICE MANUAL 1975 SCORPION SUPER STINGER 4 Movable sheave should slide off spline easily Next remove spring and retainer See Figure 4 4 5 Remove snap ring retainer and idler bearing if necessary See Figures 4 5 and 4 6 4 4 FIG 4 4 SERVICE MANUAL 1975 SCORPION SUPER STINGER 6 If necessary to remove stationary sheave sert plug 2 13 16 long x 3 4 diameter in statio
30. edures involving measurement of fuel con sumption horsepower and noise level Contrary to popular belief the exhaust system is not only for quieting the engine but also serves to in crease horsepower output by as much as 25 Changes made to the original equipment exhaust system by changing any component in the system can result in loss of power and or severe engine damage For these reasons intermediate lengths of pipe between the cylinder and the muffler are particularly critical TUNED MUFFLERS Tuned mufflers allow the engine to exhaust its spent charge into an adequate volume and properly matched muffling system More im portant the mufflers that are tuned incorporate designs that suck the exhaust gas from the cylin der allowing fuel and air to rapidly replace it and also cram over scavenged fuel and air mixture from the exhaust pipe back into the cylinder using sound waves and sound energy This is ac complished at the speed of sound which allows the engine to produce higher torque at higher RPMs Donaldson FIG 1 2 Tuning Courtesy of Donaldson Mulfier Co FIG 1 3 SERVICE MANUAL 1975 SCORPION SUPER STINGER HOW TUNING WORKS The megaphone effect of the expanded intake tube scavenges exhaust gas from the cylinder allowing rapid replacement of the fuel air mix ture from the crankcase Reflected sound waves and sound energy stop over scavenging and return fuel air mixture to the cylinder It gi
31. elt Pulley Assembly Insert a 3 16 drill or a suitable punch through the indexing hole into the im peller body With a 17 mm socket wrench remove the fan nut lock washer pulley halves and spacers See Figs 1 7 1 8 1 9 FIG 1 8 FIG 1 9 SERVICE MANUAL 1975 SCORPION SUPER STINGER D Flywheel Magneto Remove the crankshaft nut using a 27 mm socket wrench Pull the flywheel by attaching flywheel puller 444 3 1 843 2 to the flywheel flange using bolts provided Screw the three bolts through the puller into the flange and tighten evenly With a socket wrench tighten the puller bolt until the flywheel loosens on the crankshaft See Figs 1 10 1 11 1 12 1 13 FIG 1 11 FIG 1 12 NOTE It is important that care is taken to remove the positioning key in crank shaft before attempting to remove the flywheel assembly Failure to do this could result in damage to advance mechanism FIG 1 13 SERVICE MANUAL 1975 SCORPION SUPER STINGER Intake Manifold Assembly Remove the four 4 intake manifold nuts and washers Remove manifold assembly and insulators See Figs 1 14 11 5 EI Il oo oo FIG 1 15 SERVICE MANUAL 1975 SCORPION SUPER STINGER F Fan Housing and Armature Plate Assembly Remove screw holding spark plug wire bracket to fan housing With a socket type 5 mm Allen wrench and impact driver remove the four 4 mounting bolts holding fan housing to crankcase See
32. eplace armature plate 2 Replace external coil 3 Replace condenser 4 Replace points 1 Replace plugs Determine that correct plugs are being used CHECK ENGINE TROUBLE SHOOTING 1975 Scorpion Super Stinger Service Manual Clutch Drive Section SERVICE MANUAL 1975 SCORPION SUPER STINGER DRIVE SYSTEM Functional Description The main elements included in this system are 1 Drive Clutch Drive Belt Driven Clutch Chain Case with sprockets chain and chain tensioners m mm oM Drive shaft with track drive sprockets The power from the engine is transmitted through this system to the track in sequence of elements listed above to propel the machine The drive clutch belt and driven clutch serve as a torque converter The torque converter on the snowmobile down shifts to a lower ratio as the track load in creases as readily as it up shifts when the track load decreases To accomplish the automatic shifting the movable sheave of the driven clutch is fitted with a helical ramp which is guided by a follower This sheave is con trolled by a spring pre stressed in torsion and compression to hold the sheaves together at the maximum pitch diameter Under acceleration the torque from the engine is greater than the demand from the track The drive clutch then closes forcing the belt outward between the sheaves Belt tension and wedging action is unbalanced ot the driven clutch and the sheave faces are wedg
33. ion Check and replace broken or weak chain tensioners Replace bearings Disassemble and check chain sproc kets and chain case cover seal O ring re place worn parts and reassemble Refill with oil check level and check for leaks 1975 Scorpion Super Stinger Service Manual Suspension Section SERVICE MANUAL 1975 SCORPION SUPER STINGER FUNCTIONAL DESCRIPTION The four main elements of a snowmobile suspen sion are Skis Track Suspension Seat Operator P mc All elements work together to perform the sus pension functions to the optimum degree The suspensions are basically designed to 1 Protect the operator from physical abuse or injury 2 Keep the operator from being ejected from his operating position and controls 3 Prevent damage to the machine 4 Increase ground contact and improve trac tion On the 1975 Super Stinger the track suspension Para Rail Snowmobile Suspension is a unit type suspension which simply means that it is a single unit working as a whole as opposed to the multiple unit bogey type suspension It also possesses the advantage of being able to tra verse marginal snow conditions without damag ing effects to the suspension system 5 2 SERVICE MANUAL 1975 SCORPION SUPER STINGER FIG 5 1 PARA RAIL O GROUP 5 3 SERVICE MANUAL 1975 SCORPION SUPER STINGER SUSPENSION SYSTEM REMOVAL DISASSEMBLY ASSEMBLY For the removal maintena
34. l bell housing checking alignment with stub on torque plug provided for this purpose Place spring washer and bell retainer bolt on next assuring that the bolt has bottomed out securely in proper align ment Install clutch attaching bolt Torque on both bolts to 50 ft Ibs 4 7 SERVICE MANUAL 1975 SCORPION SUPER STINGER DRIVEN CLUTCH DISASSEMBLY 1 Remove chain case cover 2 Remove chain tensioners unbolt and remove top sprocket and chain DRIVEN SHAFT T d LOCKING BOLT TOP SPROCKET CHAIN CHAIN lt TENSIONER BOTTOM SPROCKET FIG 4 12 4 8 SERVICE MANUAL 1975 SCORPION SUPER STINGER 3 Remove driven unit from chaincase tapping shaft lightly with plastic mallet Remove snap ring and washer from cam top and slide off shaft See Figures 4 13 4 14 4 15 HELICAL RAMP CAM BOTTOM FIG 4 13 FIG 4 14 SERVICE MANUAL 1975 SCORPION SUPER STINGER 4 Remove key and main spring See Figure 4 16 5 This should allow cam bottom and movable sheave to be removed as a unit See Figure 4 17 and disassembled if necessary See Figure 4 18 FIG 4 17 CAM BOTTOM 4 10 SERVICE MANUAL 1975 SCORPION SUPER STINGER 6 Stationary sheave may then be unbolted from clutch shaft See Figures 4 19 and 4 19A and bearings can be pressed off if necessary STATIONARY SHEAVE CLUTCH SHAFT FIG 4 19 FIG 4 19 A 4 11 SERVICE MANUAL 1975 SCORPION
35. le valve 28 The metering lever spring 29 tran smits a force through the metering lever 30 and seats the inlet needle valve 28 against pressure The metering diaphragm 10 is pulled upward by engine suction which is tran smitted through the idle discharge port idle hole 14 secondary idle holes 16 and part throttle feed holes 17 The diaphragm action depresses the metering lever 30 and unseats the needle valve 28 and allows the fuel to enter the metering diaphragm chamber 31 and pass through the idle take off 11 Check valve 32 is forced open passing fuel into the main 21 which also feeds the throttle holes 17 Fuel only is fed through all discharge oles FIG 2 1 STARTING CHOKE OPERATION Venturi Power needle Morena Main fuel nozzle 21 Throttle bore darote valve ition 32 J part throttle position I irm giam Part throttle holes 17 lever 30 Secondary idle holes 16 ____ Idle discharge port 14 spring 29 Needle valve 28 Idle take off 11 T ER A ii MME il X FG Idle needle Es i 75 Metering Impulse int 9A diaphragm _ a ON diaphragm 10 chamber 1 Impulse fitting ext 9 2 Fuel pump diaphragm 4 zoro Flow channel 6 Channel 8 p Outlet check i valve 7 HERES E eee a Inlet check valve 5
36. llow pin to push into piston and install pin Install second circlip See Fig 1 33 for correct orientation of circlips FIG 1 34 SERVICE MANUAL 1975 SCORPION SUPER STINGER Install base gaskets on the cylinder studs and position against the cylinder flanges see Fig 1 36 With the use of a ring compressor lower cylinders one at a time over the pistons Install base washers and nuts finger tight See Fig 1 37 1 38 Temporarily install the intake manifold without gaskets and tighten manifold nuts to sixteen 16 to eighteen 18 foot pounds See Fig 1 39 Cylinder base nuts may now be torqued to sixteen 16 to eighteen 18 foot pounds as outlined on specification page The proper piston height can be measured at the top of the cylinder The edge of the crown of the piston must not protrude above the top of the cylinder with the piston in the top dead center position If the piston does protrude above the cylinder a thicker base gasket must be used See specification page for dimensions and color coding It is important that only one cylinder at a time be adjusted or the crankcase will separate and lose it s seal FIG 1 38 SERVICE MANUAL 1975 SCORPION SUPER STINGER Oil cylinders and pistons before installing cylinder heads Install head gaskets with the wide side of inner metal flange of the gaskets up toward the cylinder heads Torque cylinder head nuts to sixteen 16 to eighteen 18 foot poun
37. ly Missing at high speed or intermittent spark 11 12 13 14 1 HO an amp N _ NO PROBABLE CAUSE Air leak in crankcase or inlet system Primary wire broken Engine not timed properly Secondary wire not connected or spark plug protector not installed properly Spark retarding mechanism not working properly Pistons or rings worn Faulty carburetor Incorrect carburetor idle adjustment Spark plugs improperly gapped or dirty Head gasket blown or leaking Loose or broken magneto wires Magneto breaker points improperly gapped or dirty Weak coil or condenser Improper fuel mixture 1 Too much oil 2 Too little oil Leaking crankshaft seal Spark plugs improperly gapped or dirty Loose or broken magneto wires Magneto breaker points improperly gapped or dirty Weak coil or condenser Heat range of spark plug incorrect Leaking head gasket Engine improperly timed 11 12 13 14 MOS ns Na M REMEDY Check crankcase pressure 3 6 PSIG Repair or replace primary wire Re time engine Secure secondary wire or spark plug protector Repair retard mechanism Replace as necessary Check carburetor check valve Refer to Carburetor Section Adjust idle Refer to Carburetor Section Clean adjust or install new plugs Replace gasket
38. n spring is properly engaged in the retaining hole in reel hub FIG 1 59 1 28 10 11 12 13 SERVICE MANUAL 1975 SCORPION SUPER STINGER Install friction plate 5 over reel hub Manipulate plate until eye end of return spring engages and locks crosswise in retaining slot Rotate friction plate until the three notches are aligned with pawls when pawls are at the recoil position Install flatwasher 8 lockwasher 12 and nut 11 Tighten nut securely Untie the temporary knot in free end of rope and install the rope handle Tie a permanent knot and fit handle securely Check starter for proper operation When handle is pulled outward pawls should move outward NOTE If main spring is to be installed without the use of a spring winding tool wind main spring into case in an anti clockwise direc tion Clockwise installation on the winding tool is necessary to ensure correct anti clockwise installation of the spring when tool is placed upside down in the case FIG 1 62 FIG 1 63 1 29 SERVICE MANUAL 1975 SCORPION SUPER STINGER TIMING PROCEDURE NOTE Recoil starter carrier lower pulley assem bly and spark plugs should be removed before beginning timing procedure A Install the dial indicator assembly into spark plug hole of No 1 cylinder P T O side See Fig 1 64 B Attach negative lead of ohmmeter to engine 2i ground Attach positive lead of ohmmeter to FIG 1 6
39. nary center hole and re insert bell retainer bolt Tightening bell bolt will force stationary off crankshaft See Figure 4 7 FIG 4 7 7 Removing torque plug retainer will allow torque plug to be removed and inspected See Figure 4 8 FIG 4 8 4 5 SERVICE MANUAL 1975 SCORPION SUPER STINGER 8 Detaching springs and weight arm retainers will allow weight arms to be removed See Figures 4 9 4 10 4 11 DRIVE CLUTCH INSPECTION Inspect weight arm bushings and rollers for cracks and flat spots Also check snap rings on weight arm shaft ends Inspect torque plug for fit and wear Should have no more than 020 space between torque plug and casting Inspect idler bearing for freedom of rollers and M retention of lubricant FIG 4 10 Inspect snap ring groove on stationary and spring retainer for wear Inspect bell housing for cracks particularly in center area near spline 4 6 SERVICE MANUAL 1975 SCORPION SUPER STINGER RE ASSEMBLY OF DRIVE CLUTCH CAUTION stationary has been removed assure that there is no grease on either the shaft or sheave before re assembly Re install idler bearing snap ring retainer and spring Place weight arms on movable sheave af ter checking them for lubrication Attach retainers checking to see that the small locating hole in the bearing aligns with the detent on in ner face of retainer Install torque plug and torque plug retainer Instal
40. nce and installation of the Para Rail Snowmobile Suspension we will refer to the Para Rail group for iden tification of component parts by the numbers 1 through 57 A REMOVAL l Remove the two hex cap screws 56 and washers 57 2 Raise and block rear of vehicle off the ground NOTE In Figs 5 3 through 5 6 the track has been removed for clarity of illustration 3 Remove the two nuts 51 from the two eye bolts 11 5 4 SERVICE MANUAL 1975 SCORPION SUPER STINGER 4 Remove the two whiz lock screws 20 securing the rear suspension plates to the rear axle 5 Release the track tension by loosening the two screws 46 6 Remove hex screws 53 and nut 54 on the two suspension plates Remove plates 5 5 SERVICE MANUAL 1975 SCORPION SUPER STINGER 7 Remove the two whiz lock screws 20 located on the side of the tunnel in front of the footrests The para rail can now be removed from the track and tunnel B DISASSEMBLY PARA RAIL SNOWMOBILE FIG 5 7 SUSPENSION 1 Bracket axle adjustment 42 Remove the four 4 hex screws 21 and lock nuts 22 FIG 5 8 5 6 SERVICE MANUAL 1975 SCORPION SUPER STINGER 2 Springs 2 4 Place suspension on the floor and install spring release tool To release the springs from the spools 18 the rear of Para Rail amp Snowmobile Suspension must be held down while down ward pressure is ap
41. nd brake cable Taking care to check number of shims between the chaincase and the tunnel and their specific locations remove the chaincase from the tunnel When the chaincase is reassembled to tunnel assure that the spacers go back where they were Reverse procedure to install REMOVAL OF FRONT DRIVE SHAFT Remove chaincase cover tensioners lower sprocket and chain Loosen locking collars on front drive bearings see Fig 4 21 Remove speedometer drive adaptor and flanges Slide drive shaft through chaincase mounting hole until right side clears main frame and remove lt is necessary to detach forward end of para rail to gain clearance for entire removal of front drive shaft See Suspension Section REMOVAL OF FRONT DRIVE SPROCKET Punch out spirol pins see Fig 4 21 4 22 Then taking care to see that the shaft is clean slide sprockets off To reassemble reverse procedure LOCKING COLLARS SPIROL PINS FIG 4 21 4 14 SERVICE MANUAL 1975 SCORPION SUPER STINGER SPIROL PIN FIG 4 22 BEARING BRG FLANGES Inspection of Drive Shaft O RING FIG 4 23 Observe shaft for signs of stress cracks and ben ding check bearings and collars for breakage Check sprockets for loosening of pin holes NOTE Small cracks in the white material of the drive sprocket are not signs of failure but a result of shrinkage during manufacture SERVICE MANUAL 1975 SCORPION SUPER STINGER TROUBLE SHOOTING The
42. o the upper and lower sections of the silencer Replace as necessary Use de icers developed speci fically for use with diaphragm carburetors Do not use regular automo bile de icers 1975 Scorpion Super Stinger Service Manual Electrical Section SERVICE MANUAL 1975 SCORPION SUPER STINGER ELECTRICAL SYSTEM The Scorpion Super Stinger Snowmobile Electrical System is divided into four 4 subdivisions Power Generation Ignition Voltage Regulation Electrical Control and Distribution oos POWER GENERATION Functional Description Electrical AC power used for lighting and tacho meter operation is generated by rotating a per manently magnetized flywheel around two sta tionary coils 1 120 watt and 1 23 watt The no load voltage increases with engine RPM and could reach 32 volts RMS To maintain the voltage at the required system level 13 14 volts an external voltage regulator is utilized See VOLTAGE REGULATION MAIN ELEMENTS 1 Magnetic Flywheel 2 120 watt coil mounted on stator plate 3 23watt coil mounted on stator plate LIGHTING COILS ENGINE CONNECTOR FIG 3 1 POWER GENERATION SCHEMATIC 3 2 LIGHTING COILS ENGINE CONNECTOR FIG 3 3 SERVICE MANUAL 1975 SCORPION SUPER STINGER IGNITION Functional Description See SCHEMATIC FIG 3 8 Rockwell engines are equipped with a flywheel magneto type ignition An electrical current is generated by rot
43. olored rubber plug See FIG 2 9 Install correct needle Inspect and replace as necessary SERVICE MANUAL 1975 SCORPION SUPER STINGER TROUBLE SHOOTING CHART TROUBLE Engine runs hot spark plugs burn Fuel lean condition 2 14 PROBABLE CAUSE 1 Dirt in fuel channels 2 Metering lever adjust ment incorrect 3 Leaky nozzle check valve diaphragm 4 Hole in metering diaphragm 5 Impulse line leaking or pinched 6 Intake manifold gasket leaking 7 Leaking insulation plate between carburetor and manifold 8 Leaking diaphragm check valve 9 Fuel pump diaphragm check valve worn 10 Fuel inlet screen dirty 11 Restrictions of fuel from main supply 12 Air intake silencer leaks 13 Damaged diaphragms From incorrect de icing 10 tT 13 REMEDY Disassemble wash and blow clean See FIG 2 13 Should be 020 above surface of valve body as shown Replace diaphragm Replace diaphragm Replace as necessary Replace as necessary Replace as necessary Replace diaphragm check valve assembly See pro cedure P 2 8 Replace fuel pump diaphragm Remove bottom plate and clean screen Check complete system from fuel pick up in tank to carburetor making sure fuel pick up is staying in fuel and tank is vented sufficiently Repair or replace as quired Insure that metal clamps hold the rubber bellows securely t
44. operly gapped or points dirty 3 Faulty coil or condenser 3 Replace coil or condenser 4 Loose or broken magneto A Repair or replace magneto wires wires 5 Blown head gasket 5 Replace head gasket 6 Inlet lever adjustment 6 Refer to too low Carburetor Section 7 Crankcase leaking 7 Install new seal Good spark but 1 engine runs Leaking cylinder head Check head for warps cracks Install new gasket and cylinder cylinder head 2 Magneto wires broken 2 Repair or replace wires inside coil ground broken 3 Cracked cylinder wall 3 Replace faulty cylinder 4 Defective spark plug 4 Clean adjust or install new plug 5 Breaker points improperly 5 Re adjust points gapped 6 Crankcase seal leaking 6 Install new seal No acceleration Idles 1 Low speed needle set too l to7 well but dies down lean Adjust carburetor when put to full 2 Dirt behind needle and seat Refer to Carburetor throttle 3 High speed jet obstructed Section 4 Inlet lever set too low 5 Choke partly closed 6 Silencer obstructed 7 Fuel pump not supplying enough fuel due to 1 Punctured diaphragm 2 Flapper valves distorted 8 Fuel line obstructed 8 Remove fuel line Clear obstruction Replace line 9 Not enough oil in gas 9 Refuel using specified fuel oil mixture 10 Breaker points improperly 10 Adjust clean or install new gapped or dirty points 11 1 36 Engine improperly timed
45. plied with the right arm and upward pressure with the left arm 3 Linkage Arm 30 Remove the two screws 25 washers 426 and 48 Remove the two button head screws 33 and spring retainers 32 5 7 SERVICE MANUAL 1975 SCORPION SUPER STINGER 4 Bogey Wheel 29 Remove shaft 28 and this will allow the bogey wheel 29 tube spacers 8 tube spacers 49 bearing 5 and remaining washers 48 to be free from suspension Fig 5 12 5 Spools 18 Remove the two screws 25 and washers 26 from the wheel shaft 23 Push shaft through rails 6 and spools are removed Fig 5 13 6 Rails 6 Remove the remaining eight 8 screws 25 and washers 26 This will allow the rails to be removed from the remaining shafts bogey wheels and tube spacers The Para Rail Snowmobile Suspension is com pletely disassembled at this time 5 8 FIG 5 13 FIG 5 14 SERVICE MANUAL 1975 SCORPION SUPER STINGER C ASSEMBLY 1 Prior to assembly procedure ensure fhaf all components are clean and all defective parts have been replaced 2 Applyacoat of low temperature grease to all shafts prior to assembly Scorpion clutch lube 906800 may be used 3 Reverse procedure as outlined for disassem bly NOTE Ensure that all tube spacers and bogey wheels are assembled in their respective areas on the shafts Torque requirements for assembly are ITEMS TORQUE 20 50 60 Ft
46. pressed fuel air mix ture burns and expands thereby forcing the piston downward on a power stroke As the downward stroke of the piston turns the FIG 1 1 crankshaft it also starts to compress the fuel air mixture the crankcase and simultaneously opens the exhaust port and closes the intake port See Figs 1 1 B amp C SERVICE MANUAL 1975 SCORPION SUPER STINGER After the exhaust port is fully open and the in take port is fully closed further piston travel starts to open the transfer ports The com pressed fuel air mixture from the crankcase then travels up the transfer ports and into the combustion area After most of the burned exhaust gases have left the cylinder an incoming charge of fuel air mixture scavenges the combustion area giving it a fresh charge and the cycle is then repeated See Fig 1 1 D Because lubrication is dependent on the mixing of oil and fuel it is extremely important that good quality oil and gasoline are properly mixed The proper ratio of oil to gasoline will prevent possible engine overheating piston or cylinder scoring or eventual engine seizure Too much oil and not enough gasoline can lead to incomplete combustion fouled plugs carbon build up and muffler clogging SERVICE MANUAL 1975 SCORPION SUPER STINGER EXHAUST SYSTEMS SELECTION Selection of an exhaust system including exhaust manifold intermediate pipes elbows and muffler is a result of thorough test proc
47. r needle 22 This is noted by comparing Fig 1 and Fig 4 At full throttle operation fuel passes around the power needle 22 and is discharged through the main nozzle 21 During full throttle air is mixed with fuel in the main nozzle 21 through the nozzle air bleed 25 Suction or vacuum created by the engine s piston action draws fuel and air as the ports are exposed by position of the throttle valve 24 23 FIG 2 4 FULL WIDE OPEN THROTTLE OPERATION AAR b M a A av KAA 7 8 P 3d T Q a ee a a SSS wan f ammm j 1 i d ay 12345 6 22 19 21 18 17 16 15 14 13 12 11 10 SERVICE MANUAL 1975 SCORPION SUPER STINGER DISASSEMBLY OF PLATES GASKETS AND DIAPHRAGMS FOR CLEANING To remove the plates gaskets and diaphragms from the lower part of the carburetor body remove the four mounting screws Lay each part on a clean surface in the sequence removed See FIG 2 5 1 Cover Assembly 8 Fuel Pump Diaphragm 2 Fuel Inlet Gasket 9 Fuel Pump Gasket 3 Filter Screen 10 Fuel Pump Leaf Gasket 4 Filter Plate 11 Valve Springs 3 5 Check Valve Diaphragm 12 Pressure Spring 6 Fuel Pump Check Valve Gasket 13 Metering Diaphragm Assembly 7 Fuel Pump Plate 14 Metering Diaphragm Check diaphragms and gaskets thoroughly for cracks or leaks by holding them against light
48. riction plate 4 on reel hub until eye end of return spring 9 aligns with retaining slot Remove friction plate Fig 1 52 1 53 Remove the three pawls 3 Fig 1 54 Remove return spring 9 spring 6 and cup washer 7 Fig 1 53 Note position of plain end of return spring in the spring retaining hole in reel hub Unwind the rope lift and untie the knotted end from center hub of reel remove reel 2 Fig 1 55 Lift long rolled end of main spring 5 from the fixed spring retaining pin in the case and carefully remove the spring Fig 1 56 15 16 ij 1 12 8214 9 ES HEX of 7 6 10 18 19 20 FIG 1 49 1 25 SERVICE MANUAL 1975 SCORPION SUPER STINGER 7 Clean all parts except rope using a suitable cleaning solvent If rope requires cleaning wash it in a solution of soap and water Thoroughly dry all parts after cleaning 8 Inspect all parts for obvious damage and wear FIG 1 50 FIG 1 52 FIG 1 53 1 26 SERVICE MANUAL 1975 SCORPION SUPER STINGER FIG 1 55 FIG 1 56 1 27 SERVICE MANUAL 1975 SCORPION SUPER STINGER Assembly 1 Replace defective parts 2 Install main spring as follows a Secure main spring winding tool part number 43 0797 60 or equivalent tool circular end up in a suitable bench vise b Start with the long rolled end of main spring 5 and wind spring into circular end of tool in a clockwise direction
49. sion chamber Clean out exhaust port 5 Spark plug too hot 5 Install specified spark plugs 6 Engine fan belt loose or 6 Replace or adjust broken 7 Air leak in manifold 7 Tighten nuts or change gaskets 8 Crankcase seal leaking 8 Fit new seal Vibrates excessively 1 Idle or high speed carbu 1 to 5 Adjust carburetor Refer or runs rough and retor adjustment too rich to Carburetor Section smokes 2 Choke not opening properly bent linkage 3 Inlet control lever too high carburetor floods 4 Idle air bleed plugged 5 Welch plug loose 6 Muffler obstructed 6 Check and clear muffler 7 Engine not secured tightly 7 Tighten engine mounting to engine support bolts 8 Water in gas 8 Add carburetor de ice fluid as required 1 35 SERVICE MANUAL 1975 SCORPION SUPER STINGER TROUBLE SHOOTING CHART TROUBLE PROBABLE CAUSE REMEDY Won t start kicks back 1 Spark plug wires reversed 1 Install wire correctly and backfires 2 Flywheel key missing or 2 Replace key sheared 3 Faulty condenser 3 Replace condenser 4 Improper timing 4 Re time engine 5 Faulty breaker points 5 Adjust or replace points 6 Unhooked spark retarding 6 Reconnect mechanism or mechanism or spring replace spring broken No acceleration low 1 Spark plugs improperly 1 Clean adjust or install new top R P M hard to gapped or dirty plugs start 2 Magneto breaker points 2 Clean adjust or install new impr
50. spacers gaskets and intake manifold Fig 1 44 Torque nuts evenly to sixteen 16 to 18 foot pounds Upper Fan Pulley Assembly Install the tapered washer Install pulley half shims second pulley half tapered washer lock washer and nut Use 3 16 drill bit or punch to hold fan assembly and tighten nut See Fig 1 45 Flywheel Assembly Check advance mechanism for free operation lubricate inside cam surface Grooved area Slide assembly over crankshaft and align key ways FIG 1 44 1 23 SERVICE MANUAL 1975 SCORPION SUPER STINGER install key lockwasher and nut in that order Tighten securely See Fig 1 46 Follow Timing Procedure Section as next step I Lower Fan Pulley Assembly Install pulley half belt second pulley half recoil carrier lockwashers and bolts evenly while rotating crankshaft The proper belt deflection should be 1 8 on each side Proper adjustment can be made by adding or removing shims between upper pulley halves See Fig 1 47 J Recoil Starter Install the recoil starter assembly and tighten securely See Fig 1 48 1 24 FIG 1 46 FIG 1 48 SERVICE MANUAL 1975 SCORPION SUPER STINGER RECOIL STARTER Disassembly See Fig 1 49 for recoil start breakdown and Fig 1 50 for Recoil Starter Assembly 1 Recoil Starter Remove retaining nut 11 spring washer 12 and Thrust washer 8 from threaded shaft of reel hub Fig 1 51 Manipulate f
51. tion Remove dial indicator assembly and install in No 2 cylinder fan side See Fig 1 71 Attach positive lead of ohmmeter to No 2 cylinder terminal in connector housing Rotate flywheel counterclockwise to top dead center Set dial indicator to zero Again move centrifugal weights in flywheel to full advanced position Rotate flywhel coun terclockwise while watching dic indicator The needle must make one ful revolution and stop at between 102 and 112 At this point needle should move to left indicating point contact closed If this does not occur points need slight adjustment Re check procedure FIG 1 70 FIG 1 71 SERVICE MANUAL 1975 SCORPION SUPER STINGER TROUBLE SHOOTING CHART TROUBLE Manual starter rope comes out but pawls PROBABLE CAUSE Lack of friction plate return spring action 1 REMEDY Check friction plate return spring Replace as required Repair or replace don t engage 2 Defective pawls 2 Check for broken or bent pawls Replace pawls as re quired Manual starter rope 1 Recoil spring broken or 1 Replace spring doesn t return bent 2 Pulley housing warped or 2 Replace housing bent 3 Starting pulley worn 3 Replace pulley Electric starter 1 Loose electrical 1 Retighten connections inoperative connections 2 Poor ground 2 Secure ground connection 3 Faulty battery or circuits 3 Check recharge or replace battery 4 Faulty el
52. vere engine damage 1 6 SERVICE MANUAL 1975 SCORPION SUPER STINGER TABLE OF SPECIFICATIONS TORQUE SPECIFICATIONS 2 440 3 2 400 6 2F 440 5 CYLINDER HEAD NUTS Dra 28 to 32 ft Ibs CYLINDER BASE NUTS 16 to 18 ft Ibs FLYWHEEL NUT i 44 to 50 H Ibs 56 to 72 ft lbs 56 to 72 ft Ibs INTAKE MANIFOLD NUTS 16 to 18 ft lbs FAN HOUSING SCREWS 16 to 18 ft Ibs FAN WHEEL NUT 22 to 24 ft Ibs RING GEAR SCREWS 6mm 6 to 7 ft Ibs not applicable not applicable RING GEAR SCREWS 8mm 10 to 12 ft Ibs not applicable 10 to 12 ft lbs Tightening Sequence for Cylinder Base Nuts e ML GY 49 PTO SIDE Tightening Sequence for Cylinder Head Nuts Fan Housing Ring Gear Flange Intake Manifold and Recoil Starter Clamps 3 74 75 782 75 4005 5 2905 440s 340s All previous 6 models e 26 SERVICE MANUAL 1975 SCORPION SUPER STINGER ROCKWELL TWIN CYLINDER ENGINES F MODELS 2F 400 8 2F 440 8 DISASSEMBLY A Recoil Starter Remove four 4 screws holding the recoil assembly to the fan housing See Fig 1 4 See pages 1 28 A B C for recoil starter disassembly FIG 1 B Lower Fan Pulley and Carrier Assembly IG 1 5 Remove the three 3 hex head bolts on the carrier Remove carrier lower pulley assembly and V belt See Figs 1 5 1 6 FIG 1 6 1 8 SERVICE MANUAL 1975 SCORPION SUPER STINGER Upper Fan B
53. ves a supercharging effect even though it operates from the exhaust rather than the intake side Over scavenging is also retarded by moderate muffler back pressure Silencing is accomplished after power is maximized by acoustical packing in the resonator outlet tube plus chambering and baffling which gives an effective 2 pass muffler design SERVICE MANUAL 1975 SCORPION SUPER STINGER TABLE OF SPECIFICATIONS ENGINE MODEL DESCRIPT ne 2F 440 3 2F 400 8 2F 440 8 2 658 2 559 2 658 BORE 67 5mm 65 0mm 67 5mm STROKE 2 362 DISPLACEMENT IN cc COMPRESSION RATION actual IGNITION SYSTEM Bosch Flywheel Magneto 12V 75W 12V 150W 12V 150W TIMING BEFORE TDC CENTRIFUGAL 102 112 WEIGHT ADVANCED j TIMING BEFORE TDC CENTRIFUGAL T i WEIGHT RETARDED 018 to 020 018 to 020 018 to 020 BREAKER POINT GAP 014 to 016 LIGHTING COIL VOLTAGE AND OUTPUT SPARK PLUG THREAD 14mm 1 25 3 4 reach 020 020 020 SPARK PLUG 0 5mm 0 5mm PARK PLUG BOSCH ORIGINAL EQUIPMENT W260T2 W260T2 TYPE OF ENGINE COOLING Axial Picw Fon ROTATION OF CRANKSHAFT Counterclockwise PTO side W260T2 FUEL OIL RATIO As Specified on Scorpion Oil Container GASOLINE 95 octane minimum lead free not acceptable Special 2 Cycle Snowmobile Oil TYPE OF OIL Do not exceed indicated advance as this will result in se
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