- -- -- -- -- - - - -- - - - - -- - (/"- ) 1975 Scorpion Brut J Service Manual Engine Section ) 1-l
SERVICE MANUAL· 1975 SCORPION BRUT ENGINE SYSTEM General Description: The Scorpion Brut e ngine is especially designed and built for today's high performance snowmobile. Any internal combusion engine performs best and is most reliable at a constant operating temperature. The Scorpion Brut engine is thermostatically controlled to run at a 180 degree+4 degree F cylinder head temperature whether the outside temperature is -30 degree F or +50 degree F.
SERVICE MANUAL · 1975 SCORPION BRUT After the exhaust port is fully open and the intake port is fully closed, further piston travel starts to open the transfer ports. The compressed fuel/air mixture from the crankcase th en 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. (Fig. INTAKE 1-lD).
SERVICE MANUAL · 1975 SCORPION BRUT TABLE OF SPECIFICATIONS IDENTIFICATION SIZE TORQUE Cylinder Head Nuts 8mm 20Ft. lbs. Cylinder Base Nuts 10 mm 25Ft. lbs. Flywheel Nut 45-50 Ft. lbs. Intake Manifold Nuts 8mm 20Ft. lbs. Exhaust Manifold Nuts 8mm 20Ft. lbs. Water Manifold Nuts 6mm 15Ft. lbs. Crankcase Bolts 8mm 20Ft. lbs. 10 mm 25Ft. lbs.
SERVICE MANUAL· 1975 SCORPION BRUT ENGINE REMOVAL ( 1. 2. Separate the carburetors from the engine by removing the clamps which secure the rubber connectors to the carburetor outlet. CLAMPS Remove the 3/8" nuts which fasten the tie rod ends to the steering frog. Remove the cotter key from the lower end of the steering frog. Remove the 2lf4" bolts which secure the upper steering bracket to the roll bar. FIG. 1·2 CARB. ELBOW MOUNTING SCREWS FIG.
SERVICE MANUAL· 1975 SCORPION BRUT Lift the steering post clear of the engine area. UPPER STEERING BRACKET / f FIG. 1·4 3. Disconnect the engine electrical connectors, spark plug leads and the temperature light wire from th heat sensing element. FIG. 1-5 SENSING ELEMENT----+-----= CONNECTOR FIG.
SERVICE MANUAL· 1975 SCORPION BRUT 4. Disconnect the coolant hoses from the manifolds and plug both manifolds and hoses to reduce coolant spillage. COOLANT BY· PASS HOSE FIG. 1-7 ( FIG.
SERVICE MANUAL· 1975 SCORPION BRUT 5. Remove 2-7 /16" lock nuts which secure the front motor mounts to the chassis. Remove the 6 - 8 mm screws which secure the rear motor mounts to the engine. 6. Release the springs which fasten the exhaust wye to the muffler. 7. lift the engine from the sled and drain the coolant. . ,, ENGINE DISASSEMBLY I ASSEMBLY Disassembly (Peripheral Equipment) 1. Remove the carburetor to engine Elbow connectors. (2 socket head screws/elbow) See Fig . 1-2. 2.
SERVICE MANUAL· 1975 SCORPION BRUT 4. Remove the coolant inlet and outlet manifolds. (6 mm nuts). 5. Disconnect the water pump mounting brackets. (3 - 8 mm bolts). 6. Remove the front motor mounts from the engine. COO~ANT OUTLET MANIFOLD COOLANT INLET MANIFOLD FIG. 1-12 FIG.
SERVICE MANUAL· 1975 SCORPION BRUT Engine Disassembly 1. Remove heads. Remove 8 mm nuts (6 per head). Pry up carefully to separate heads from cylinder. 2. Remove cylinders. Remove 10 mm cylinder nuts. Slide cylinders off pistons. FIG. 1-14 ~--- HEAD NUTS FIG. 1-15 CYLINDER NUTS ].
SERVICE MANUAL- 1975 SCORPION BRUT 3. ( Remove pistons. Extricate snap ring with snap ring pliers. SNAP RIN FIG. 1-16 Slide piston pin out of piston. Exercise care that excessive side pressure is NOT applied to the connecting rod. ( FIG. 1-17 Pull piston from connecting rod. Remove pin bearing and bearing spacers. FIG.
SERVICE MANUAL - 1975 SCORPION BRUT PTO END LOCKING STRIP 1. Remove hex locking strips. 2. Remove seal. 3. Remove ga sk e t. head bolts ---------1~ ) ~' with FIG. 1-19 ) MAGNETO END 1. Remove Recoil Starte r . Tak e h ex head screws out. Pull recoil off crankcase. 2. Complete Disassembly. HEX SCREWS t FIG.
SERVICE MANUAL • 1975 SCORPION BRUT 340MODEL a. 440MODEL Remove pump pulley bolts, emergency rope pulley and water pump pulley. a. Remove 6 mm pump pulley bolts, emergency rope pulley and water pump pulley. .,. .>'' "---------,.,.- --k +·~ . ~ EMERGENCY ROPE PULLEY----, ?'. '* WATER PUMP PU FIG. 1-21 b. Remove 18 mm nut holding rotor on shaft. b. Remove 18 mm nut holding rotor on shaft. FIG. 1-23 FIG.
SERVICE MANUAL- 1975 SCORPION BRUT l 440MODEL 340MODEL c. c. Pull rotor from shaft using puller. Pull rotor from shaft using puller. ROTOR FIG. 1-24 j d. Take out pulleys head screws holding magneto to crankcase. Remove magneto. d. .. Take out Phillips head screws holding magneto to crankcase. Remove magneto . FIG. 1-26 FIG.
SERVICE MANUAL· 1975 SCORPION BRUT 340MODEL e. Remove Phillips head screws holding seal to crankcase- Remove seal. 440MODEL e. Remove Phillips head screws holding seal to crankcase. Remove seal. FIG. 1-28 ) FIG.
SERVICE MANUAL- 1975 SCORPION BRUT DISASSEMBLY OF CRANKCASE 1. Remove 8 mm bolts (18-440, 12340) and 2-1 0 mm bolts. 2. To loosen crankcase, hold bottom half firmly and tap top half with plastic mallet. 3. Lift top half of crankcase off. FIG. 1-29 4. Lift crankshaft out of lower half of crankcase. FIG. 1-30 FIG. 1-31 FIG.
SERVICE MANUAL- 1975 SCORPION BRUT ENGINE ASSEMBLY ( Assemble Crankcase/Crankshaft. 1. lay lower half of crankcase on work bench. Grease. 2. Place crankshaft in crankcase with positioning ring in groove. • Install rotor key in crankshaft carefully. (440 Model only). • Grease labyrinth seal and oil bearings. FIG. 1-33 3. ( Apply gasket sealer on lower half of crankcase. • Place upper half of crankcase on lower half. FIG. 1-34 LABYRINTH SEAL ( FIG.
SERVICE MANUAL· 1975 SCORPION BRUT 4. Install crankcase bolts and torque (See Specifications: P. 1-4). ) 5. Install cylinder bose gaskets. FIG. 1-36 ) FIG.
SERVICE MANUAL • 1975 SCORPION BRUT SEAL PLATE INSTALLATION SEAL MOUNTING SURFACE \ 1 1. Measure distance from seal mounting plate surface on case to outer race of end bearing on shaft. (Use depth micrometer). 2. Select and install correct end gasket depending upon depth measurement as follows: Depth Measurement .091 and over .08 1 to .091 .080 and less Gasket Thickness .2 mm (.003") .3 mm (.0 12") .5 mm (.020") 3. Bolt seal plate in position. 4. Bend lock tabs to secure plate bolts. FIG.
SERVICE MANUAL- 1975 SCORPION BRUT PISTON INSTALLATION 1. Place piston pin bearings in connecting rods. • Position spacers at ends of bearings. • Lubricate bearings. See Fig. 1-1 8. 2. Install one {1) snap ring in each piston before placing pistons on rods. 3. Slip pistons over connecting rods holding bear.ings and spacers in position. 4. Insert piston pin through piston, bearing and spacers. elnstall remaining snap ring. See Fig. 1-16, and 1- 17.
SERVICE MANUAL • 1975 SCORPION BRUT CYLINDER INSTALLATION 1. Position cylinder so that the intake port (carburetor side) is toward side of crankcase with impulse fittings. 2. Place wooden block or other support crankcase to support piston. 3. With ring compressor over rings, slide cylinder onto piston. PISTON SUPPORT ( RING COMPRESSOR -----r FIG.
SERVICE MANUAL- 1975 SCORPION BRUT 4. With cylinders in place, place inlet coolant manifold on cylinders, I • Torque 6 mm nuts on manifold to 5 Ft. lbs. eTHEN •Tighten torque 10 mm nuts on cylinder studs securely to 25 Ft. lbs. \ ,,,,,It,. .r FIG. 1-44 INLET MANIFOLD CYLINDERS 5. Place heads on cylinders. ) HEAD NUTS ~ • Locate outlet coolant manifold on heads. J v eTorque 6 mm manifold nuts to 5 Ft. lbs. Torque 8 mm head nuts on • studs; torque to 20 Ft. lbs.
SERVICE MANUAL • 1975 SCORPION BRUT TIMING PROCEDURE POINTS CAM (340 O NLY) 1. Set point gap at maximum opening on both sets of points at .015 ". Fig . 1-46, 1-47 illustrations show specia l cam (without magnetic f lywhee l) installed so tha t gap check can be seen. Under no rma l cond i tions , t he gap w il l be checked th r ough the windows in the f lywhee l (rotor) . See Fig . 1- 49 ). ARMATURE MOUNTING SCREW CAM LLER (AT HIGH POINT ON CAM} ( POINTS MOUNTING SCREW FIG. 1-47 .
SERVICE MANUAL - 1975 SCORPION BRUT 2. Install special bolt in flywheel to hold the weight arms in the "full advance" position. WEIGH ARMS FIG. 1-48 FLYWHEEL SPECIAL BOLT FOR POSITIONING WEIGHT ARM FIG.
SERVICE MANUAL· 1975 SCORPION BRUT 3. ( Insert the dial indicator in the PTO cylinder. Fig. 1-50 shows the dial indicator in position with the heads removed for clarity. Under normal circumstances the dial indicator will be inserted through the spark ptug hole. Connect an ohmmeter with one terminal to the red lead from the magneto, the other terminal grounded to the crankcase.
SERVICE MANUAL - 1975 SCORPION BRUT 4. Locate top dead center of the pist on travel. Set the dial indicator on zero. See Fig. 1-50. 5. Rotate the crankshaft counterclockwise until' the indicator read s .250". Set the ohmmeter scale selector at RX1. Adju st the needle reading to 4 on the resistance scale. See Fig. 1-50. 6. Rotate the crankshaft clockwise until the ohmmeter indicates a sudden decrease in resistance. This means that the points have closed.
SERVICE MANUAL- 1975 SCORPION BRUT 7. 8. Shift the dial indicator to the #2 cylinder (magneto end). Connect the ohmmeter terminal to the white lead from the magneto. Adjust the point closing position to within .005" of the position established for the #1 cylinder. This is done by loosening the points mounting screw and adjusting the point gap in the necessary direction. (See Fig. 1- 47). ( I FIG.
( ) 1975 SCORPION BRUT ( ) Service Manual Carburetor Section (' 2- l
SERVICE MANUAL - 1975 SCORPION BRUT FUNCTIONAL DESCRIPTION: GENERAL ) Th e purposes o f the carburetor are: ( 1) to break fu e l into tiny partic les (vaporize) (2) to mix the fuel with air in the proper ratio and (3) to deliver the combustible mixture to the engine. Pulsations from the crankcase through the impul se tube actuat e th e fuel pump diaphragm to transport fuel from the tank into the carburetor.
SERVICE MANUAL • 1975 SCORPION BRUT STARTER (FUEL ENRICHING) SYSTEM (See FIG. 2·1, 2-2) ( j 1. The fuel is metered through the starter jet. 2. The fuel is broken into particles and mixed with air as it travels through the emulsion tube. r -·- -l 3. The mixture flows into the area vacated by the Fuel Enriching Valve and there is mixed with air from the intake port. : I - - ~Jt=!:=====~ ~*'(;:r,t--:; - J I -~-' 4. The final mixture is delivered to the engine intake through the fuel discharge port.
SERVICE MANUAL • 1975 SCORPION BRUT I PILOT SYSTEM (LOW SPEED OPERATION) (See FIGS. 2-3, 2-4, 2-5) 1. Conditions: a. The throttle valve is nearly closed. NEEDLE JET AIR FLOW BY-PASS b. Air velocity through the needle jet is slow, resulting in insufficient negative pressure to draw fuel from the needle jet in the main fuel system. 2. Fuel is metered through the pilot jet. 3. The fuel is mixed with air adjusted to the I I proper amount by the air screw. 4.
SERVICE MANUAL - 1975 SCORPION BRUT PRIMARY (MAIN FUEL) SYSTEM (See fig. 2-6) ) (Throttle 1/4 Open To Full Open) 1. Velocity of air flowing through needle jet increases. Differential pressure increases to force fuel flow. 2. Throttle Valve 1/4 to% open. a. Fuel passes through main jet. b. Fuel is metered in the clearance between the needle jet and the jet needle. c. Fuel is mixed with air in the needle jet. d.
SERVICE MANUAL - 1975 SCORPION BRUT FLOAT SYSTEM (FIG. 2-7) 1. This system operates to maintain a constant fuel level in the bowl. 2. The fuel flows from the fuel pump between the needle valve and valve seat into the float chamber. 3. When the buoyancy of the floats overcomes the fuel pressure, the needle valve closes, shutting off the fuel supply. 4. If the fuel level becomes too high, excessive fuel leaves the nozzle enrich-ing the mixture. 5. Too low fuel level results in a lean mixture.
SERVICE MANUAL - 197 5 SCORPION BRUT DISASSEMBLY - ASSEMBLY ( To perform maintenance, cleaning or repair operation on the Mikuni Carburetor, use the following procedure: Remove the parts as indicated and place them on a clean surface in the sequence removed . MISCELLANEOUS 1. To drain the float bowl, remove the main jet holder in the bottom of the bowl ( 14 mm wrench). ENRICHING VALVE CAP 2. Remove the jet from the jet holder (6 mm wrench). 3. Remove Enriching Valve (Starter) Assembly (12 mm wrench).
SERVICE MANUAL - 1975 SCORPION BRUT 4. Remove Air Screw (flat blade screwdriver). (Fig. 2-14). 5. Remove pilot jet screwdriver. 6. Remove air screwdriver). jet AIRSCREW (narrow, flat blade (narrow, flat blade FIG. 2-14 7. Remove idle speed screw screwdriver). (See Fig. 2-15). (flat blade IDLE SPEED SCREW THROTTLE VALVE (Fig. 2-16) 1. Remove the cap lock (Phillips screwdriver). 2. Unscrew the operation). carburetor cap (hand FIG. 2-15 3. Remove the following parts: a. Spring b.
SERVICE MANUAL - 1975 SCORPION BRUT FLOAT BOWL {FIG. 2-17, 2-18) J 1. Remove four Phillips head screws (Phillip screwdrive r) . 2. Remove float bowl. MOUNTING SCREWS ---~...;.. FIG. 2-18 FIG. 2-17 ) NEEDLE JET RETAINER FITTING - I NEEDLE JET (FIG. 2-19) 1. Unscrew retainer fitting (8 mm wrench). 2. Remove needl e jet. o• FIG.
SERVICE MANUAL · 1975 SCORPION BRUT CLEANING 1. Clean entire carburetor with carburetor cleaner or solvent. 2. Blow out all jets and passages with air or clean them with a nylon brush or something equally soft. Do not use metal wire for cleaning. Any nicks, scratches or other damage may cause the carburetor to malfunction. REASSEMBLY Reassemble in the reverse order of disassem bly. CARBURETOR ADJUSTMENTS FLOAT ADJUSTMENT (See FIG. 2-20) 1.
SERVICE MANUAL· 1975 SCORPION BRUT PILOT SYSTEM ADJUSTMENT ) 1. The pilot outlet and by -pass opening are sized to match the carburetor bore. The pilot jet opening and the air screw position are equally important. 2. Pilot Jet Size Check a. Elevate the sled so that the track is clear of the ground and start the engine. b. Open the throttle slightly and observe the speed increase characteristics. c. If the exhaust smoke is heavy and the exhaust noise dull, the pilot jet is too big. d.
SERVICE MANUAL- 1975 SCORPION BRUT NOTES: 1. The air screw position should never be more than three (3) turns open. At this point the spring ceases to function as a lock, and the screw could be lost in operation. 2. If there is a range in the air screw adjustment where the maximum engine RPM is essentially constant (i.e., 1 1/2 to 2 turns). better acceleration will be achieved at the lower setting. MAIN SYSTEM ADJUSTMENT 1.
SERVICE MANUAL - 1975 SCORPION BRUT TROUBLE SHOOTING CHART TROUBLE ( -PROBABLE CAUSE REMEDY FUEL RICH CONDITION -Engine noise dull, intermittent - Spark plugs fouled. - Heavy exhaust gases -Malfunctioning gets worse, when enriching valve is opened. 1. Damage to or foreign obstacle under inlet needle valve or valve seat. 1. Remove needle valve. Inspect, clean or replace. 2. Float arm bent to allow excess of fuel in float bowl. 2. Adjust float arm. (See ADJUSTMENTS, P. 2-11) 3. Air jet blocked. 3.
( l 1975 SCORPION BRUT ( Service Manual Electrical Section 3-1
SERVICE MANUAL - 1975 SCORPION BRUT ELECTRICAL SYSTEM The Scorpion Brut Electrical Sy stem i s divided into four sections: ) A. Power generation B. Ignition C. Voltage Regulation D. Electrical Control and Distribution POWER GENERATION BRUT 440 Functional Description: LIGHTING COILS (4) MAGNETIZED ROTOR AC power, used for lighting and controls operation, is generated by rotating a p e rmanently magnetized flywheel mounted o n the engine crankshaft past a stator which contain s lighting coils.
SERVICE MANUAL • 197 5 SCORPION BRUT TAN ( RED LIGHTING COILS (STATOR) YELLOW RED ENGINE CONNECTOR YELLOW TAN 340 BRUT FIG. 3-4 YELLOW LIGHTING COILS (STATOR) YELLOW ENGINE CONNECTORS 440 BRUT FIG.
SERVICE MANUAL - 1975 SCORPION BRUT IGNITION Functional Description: The Brut engines utilize two different type ignition systems. The 340 engine is equipped with a flywheel magneto type ignition. The 440 engine is equipped with an electronic Capacitive Discharge Ignition System. 340 Engine Ignition: MAIN ELEMENTS: An e lectrical curren t is generated by rotating a permanently magnetized flywheel about the ignition coils.
SERVICE MANUAL - 1975 SCORPION BRUT ( ' IGNITION COIL (STATOR) CONDENSER Ht· ~SPARK PLUG EXTERNAL IGNITION COILS -- ~SPARK PLUG FIG.
SERVICE MANUAL - 19.75 SCORPION BRUT 440 Engine Ignition: Electrical energy (high voltage, low amperage) is generated by rotating a permanent magnet flywheel past a pair of ignition coils. The high voltage (~200v) thus generated is absorbed by a large condenser. A special signal is also initiated by the rotating magnet which closes an electronic switch (tran sistor) every 120 degrees of rotation.
SERVICE MANUAL • 1975 SCORPION BRUT ( I IGNITION COILS -=---...-.. . . - - (MAGNETO) ROTOR ·- - - ----ENGINE CONNECTOR (CD IGNITION) ........;;;:--,.....---·t:NGINE CONNECTORS (LIGHTING COIL) FIG. 3-10 CD IGNITION UNIT ---"::11 (CONTAINS CONDENSER) ~----- EXTERNAL COILS ( CONNECTOR \ :.1 - + - - - - - · - SAFETY SWITCH CONNECTOR - ENGINE CONNECTOR FIG. 3-11 , . . - - - - - - - - - - - - - - EXTERNAL COILS CDI UNIT "11'------ - SPARK PLUG LEADS CONNECTOR ... FIG.
SERVICE MANUAL • 1975 SCORPION BRUT VOLTAGE REGULATION Functional Description: The voltage regulator is connected across the lighting coils in parallel with the electrical load of the sled. Under operating conditions, the voltage drop across the regulator is such that 13.8 volts RMS is supplied to the snowmobile lighting circuit. FIG. 3-13 ) TRANSISTOR SCR MOUNTING BRACKET 3-8 VOLT AGE REGULATOR SCHEMATIC FIG.
SERVICE MANUAL - 1975 SCORPION BRUT VOLTAGE REGULATOR CHECKS ( 1 1. Resistance across regulator Two most common catastrophic failure modes of the regulator may be identified by simply checking the resistance of the regulator. a. Burned out sensing element. Normal resistance across the regulator is approximately 155 - 160 . The symptom of a burned out sensing element is a sig nificantly increased resistance reading. b. Shorted SCR.
SERVICE MANUAL • 1975 SCORPION BRUT ELECTRICAL CONTROL & DISTRIBUTION Functional Description: Power is supplied continuously to the tachometer movement, brake light switch and temperature indicator so that any time power is being generated, those items will function. Power to all other items is supplied through the ignition switch in the "lights" mode. Grounding of the wiring complished at the roll bar. system is ac- Main elements of the system are: 1. 2. 3. 4. 5. 6.
,--..._ ' """'\ WIRING SCHEMATIC FIG. 3-17 ELECTRICAL DISTRIBUTION & CONTROL 197 5 SCORPION BRUT 340 SAFETY SWITCH CONN. r-- ·....-- WHITE r---~/ I RED/WHITE .-/'- YELLOW /WHITE 1'\ Y/W TACHOMETER CONN . .-- I Y/W BROWN ENGIN~NN. R/W OJ:- r-- w IGNITION SWITCH CONN. z CONN. 7 7'- 1 SPEEDOMETER Y/W I I Y/W/B r 3: 0 Ill:: 111:1 /Ir-- 111:1 ' ~ > •fl BROWN 7 ~ m 3: )> z c: GREEN/WHITE BLUE Y/W L-- HEADLAMP CONN. Y/W/B BROWN .... w VOLT AGE REG. CONN.
SERVICE MANUAL - 1975 SCORPION BRUT WIRING CODE (ELECTRICAL DISTRIBUTION & CONTROL) BRUT 340 COLOR FUNCTION FROM TO Blue Hot (Hi) Hi-Lo Switch Connector Head l ight Connector Brown Ground Ground Ground Ground Tachometer Connector Headlight Connector Taillight Connector Engine Connector Headlight Connector Roll Bar Roll Bar Roll Bar Green/White Hot (Lo) · Hi -Lo Switch (Lo) Headlight (Lo) Red/White Hot Hot Engine Connector Safety Switch Connector Safety Switch Connector Ignition Switch
,. ' ,.._ ~ .......... '-~ SAFETY SWITCH CONN. I ENGINE CONN. c:::J--I I BLACK YELLOW /WHITE 1 I J -"'I I~II ! r- TACHOMETER CONN. . Yffl YELLOW /WI-IlTE BROWN y ffl/B r-- I BLACK IGNITION SWITCH CONN. Yffl I Y/W ~ I : /~ SPEEDOMETER CONN. z 3: 0 1111: CCI /~ r-- •II BROWN / "'m ;:a YELLOW /WHITE/BLACK < BRAKE SW. CONN. I L 0 .... .... VOLTAGE REG. CONN. I I TEMP. LIGHT CONN. WIRING SCHEMATIC FIG.
SERVICE MANUAL - 1975 SCORPION BRUT WIRING CODE {ELECTRICAL DISTRIBUTION & CONTROL) BRUT 440 COLOR FUNCTION Black FROM TO Engine Connector Safety Switch Connector Safety Switch Connector Ignition Switch Connector Blue Hot (Hi) Hi-Lo Switch Connector (Hi) Headlamp Connector (Hi) Brown Ground Ground Ground Ground Ground Ignition Switch Connector Safety Switch Connector Instrument Connector Headlamp Connector Taillight Connector Safety Switch Connector Ground (Roll Bar) Headlamp Connector Groun
SERVICE MANUAL - 197 5 SCORPION BRUT TROUBLE SHQ,QTING (ELECTRICAL) ( ) TROUBLE No lights PROBABLE CAUSE REMEDY Open Circuit: Faulty Switch(s) Separated Connector(s) Cut Wiring Repair or replace faulty or damaged element. Wiring shorted to ground: Damaged Insulation Repair or replace damaged or faulty element. Faulty Regulator (Shorted SCR) Replace regulator. Shorted or open lighting coil. Replace stator plate. Faulty regulator- Incorrect regulator set point (too low). Replace regulator.
1 ' )
1975 Scorpion Brut ( ) Service Manual Clutch/Drive Section 4- 1
SERVICE MANUAL- 1975 SCORPION BRUT DRIVE SYSTEM Functional Description: The main elements included in this system ore: 1. Drive Clutch 2 . Drive Belt 3. Driven Clutch 4. Chain Case with sprockets, chain and chain tensioners. 5. 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.
SERVICE MANUAL - 1975 SCORPION BRUT DRIVE CLUTCH REMOVAL ) 1. Remove the 7/16 clutch bolt. 2. Remove large nut holding clutch to gether. 3. Insert a %II x 3 V4 steel plug in hollow drive clutch hub. Use large nut with plug as puller to remove clutch. 11 7 /16" CLUTCH BOLT ) II CLUTCH ASSEMBLY NUT STEEL PLUG 0 ASSEMBLY NUT ...
SERVICE MANUAL· 1975 SCORPION BRUT DRIVE CLUTCH DISASSEMBLY 1. With clutch removed from sled, install large nut approximately one-half { 1/2) way, i.e., one-half the threads engaged . 2. Holding movable firmly with cover facing the floor, rap the large nut sharply against the floor (or some other firm object). The cover will separate from the stationary hub. 3. Remove the large nut. Remove the movable and cover from the stationary. 4. Completely disassemble clutch.
SERVICE MANUAL • 1975 SCORPION BRUT DRIVE CLUTCH ASSEMBLY ( MOVABLE 1. Insert the idl er spring i n the movable bore. Shove it far enough through that the keeper (retainer) can be installed. Th e spring tang must be in one of th e grooves in the movable bore. 2. Position the spring r etainer. SPRING TANG 3. FIG. 4-5 GROOVE Pu sh the spring back up against the retainer. In sta ll the plastic bushing. ( ' \ \ "'' \ FIG.
SERVICE MANUAL - 1975 SCORPION BRUT 4. Place washer on nylon bushing. ) CLUTCH COVER FIG. 4-8 l. Insert the bushing with washer in weight arm. BUSHING NYLON NOTE: The nylon washer always goes on the clockwise side of the weight arm when viewed looking into the clutch cover. SHOE PAN HEAD SCREW 2. W~SHER I ) 1 0 Install weight arm in cover, securing it with bolt. FIG. 4-9 FIG.
SERVICE MANUAL - 1975 SCORPION BRUT CLUTCH (COMPLETE) ) 1. 2. Place the movable sheave on the stationary sheave. Engage the inner spring tang in the hole in the stationary hub. Prepare the cover with a rubber band, holding the weight arms correctly. Insure that the shoes on the weight arms are all properly oriented. HOLE I FIG. 4-12 INNER TANG Place cover over movable. CORRECT SHOE ORIENTATION () INCORRECT ORIENTATION RUBBER BAND FIG. 4-13 FIG.
SERVICE MANUAL • 1975 SCORPION BRUT Make sure that the index marks on rim of the movable and cover are aligned. FIG. 4-15 INDEX MARKS 3. Secure clutch together with large nut. Remove rubber band. FIG.
SERVICE MANUAL· 1975 SCORPION BRUT DRIVEN CLUTCH REMOVAL (. 1. 2. Remove screw and lock wa sher, securing clutch to Jack Shaft. Pull clutch off shaft. DRIVEN CLUTCH DISASSEMBLY 1. ( Wind the movable sheave against the spring approximately 1/6 turn, and restrain it. Compress cam top against clutch spring. Slide cam in on stationary splined hub until locking inserts clear the cam top hub. SCREW (SECURING CLUTCH TO JACK SHAFT) ) CAM TOP 2. Remove locking inserts. 3.
SERVICE MANUAL • 1975 SCORPION BRUT DRIVEN CLUTCH ASSEMBLY 1. Place washer on stationary hub. Install movable stationary sheave. 2. sheave on Place clutch spring over hub of movable. FIG. 4-18 3. Insert the spring tang in the #2 hole (340). or #1 Hole (440). ) FIG. 4-19 ' / FIG.
SERVICE MANUAL - 1975 SCORPION BRUT 4. Place the cam top over the end of the spring. 5. Engage the spring end behind one of the cam lobes. 6. Rotate to cam top approximately 130 degrees. This will wind up the spring. ( The movable must be restrained during this step. 7. Push the cam top down over the splines to clear the locking insert groove. FIG. 4-21 CAM LOBE 8. ( Install inserts. Release the clutch. The cam top will snap back until the cam ramps are engaged. SPLINES ('; FIG.
SERVICE MANUAL - 197 5 SCORPION BRUT CLUTCH INSTALLATION DRIVE CLUTCH 1. Place the drive clutch over the engine PTO shaft with .010 shim between clutch bore and shaft. In sure that there is no lubrication on the shaft or in the clutch bore. 2. Insert the clutch attach bolt. (See Fig . 4-1 ) . Torque to 75Ft. lbs. DRIVEN CLUTCH 1. With the Jack Shaft in position, slide the driven clutch assembly on the end of the shaft. 2.
SERVICE MANUAL - 1975 SCORPION BRUT CLUTCH ALIGNMENT ( -............. ,"' ) 1. With both clutch assemblies installed, m easure alignment of the back sides of the stationary sheaves. ) .. , " -· - ? They should be parallel, and off set by V2 ". (See Fig. 4 -23). ALIGNMENT BAR 2. ( ) If the sheaves are not parallel, loosen the mounting bolts on the chain case and rotate the chain case to bring the sheaves into parallelism. ADJUSTMENT SLOTS FIG.
SERVICE MANUAL- 1975 SCORPION BRUT 3. If the off set is not correct, i.e., is not V2 ", remove the driven clutch and insert or remove spacer washers on end of shaft to provide the correct off set. SPACING WASHER FIG. 4-25 JACK SHAFT ) DRIVE CLUTCH ADJUSTMENT The cut-in speed of the BRUT clutch is 3800- 4200 rpm. The control speed is 7000 to 7200 rpm. To vary the shift range of the machine, add or subtract washers on the pan head screws on the weight arms. (See Fig. 4-9). (_.
SERVICE MANUAL· 1975 SCORPION BRUT BRAKE REMOVAL CABLE BRACKET () 1. Remove attaching bolts. 2. Separate control cable clevis and cable bracket. 3. Pull brake disc off splines. from jack shaft DISASSEMBLY 1. Remove cotter pin and castillated nut. Brake assembly can then be separated into component parts. FIG. 4-26 CLEVIS ATTACHING BOLTS ASSEMBLY ( 1. Insert steel plate and wear pad into recessed area in back of castings. STEEL PLATE J ' FIG.
SERVICE MANUAL· 1975 SCORPION BRUT 2. Place pins in casting holes, rounded end out. \ _.) 3. Position lever over threaded stud and washer on top of lever. 4. Install castillated nut and cotter pin. INSTALLATION FIG. 4-28 PINS DEND 1. Reverse of removal. (See Fig. 4- 26). A -- ~,.: ) WASHER FIG. 4-29 LEVER FIG. 4-30 4- 16 NUT & COTTER PIN FIG.
1975 Scorpion Brut ( ) Service Manual Suspension Section 0· . .
SERVICE MANUAL - 1975 SCORPION BRUT SUSPENSION SYSTEM Functional Description: The four main e lem ents of a snowmobile suspen sion ore: 1. 2. 3. 4. Skis Track Suspension Seat Operator All elements work together to perform the sus pension functions to the optimum degree. The suspensions ore basically designed to: 1. 2. 3. 4. Protect the operator from physical abuse or injury. Keep the operator from being ejected from his operating position and controls. Prevent damage to the machine.
SERVICE MANUAL- 1975 SCORPION BRUT SUSPENSION SYSTEM REMOVAL Th e e lements of the suspension/drive must be removed in th e following sequence: 1. 2. 3. Slide suspension Chain and chain sprockets Drive shaft SLIDE SUSPENSION REMOVAL \.......t 1. Place the sled on th e floor with a 2 " x 4" underneath the track. Plac e weight on the sled to extend the cross shaft. 2. Remove the r ea r mounting screws . Relea se w e ight. 3. Remove lock ing bolts, locks, and front mounting bolt s. 4.
SERVICE MANUAL - 197 5 SCORPION BRUT CHAIN DRIVE REMOVAL l. Re move chaincase cover. 2. Remove chain drive components. a . Remove snap ring on uppe r sprocket. b . Re move bolt on lower sprocket. c. Back out chain t e n sion tighte ning bo lt. •.. d. Sl ide sprockets and chain out toge ther. CHAIN TENSION TIGHTENING BOLT-- - - -- ,_ I - - - - -- - ( ... FIG. 5-3A LOWER SPROCKET BOLT---- -----~---' CHAIN CASE MOUNTING BOLTS (4) --- ----~ .
SERVICE MANUAL • 1975 SCORPION BRUT REMOVE FRONT DRIVE ( 1. Loosen allen screw in collar on left end of shaft just inside chaincase. 2. Rotate collar to loosen. 3. Slide collar over shaft. 4. Loosen chaincase mounting bolts. 5. Push shaft into chaincase hole. 6. Lower opposite end of shaft and pull out of tunnel. FIG. 5-4 LOCKING COLLAR SUSPENSION DISASSEMBLY SPROCKET MOUNTING BOLT 1. Remove 5/16" bolts securing sprockets to shaft. (See Fig. 5-4) . 2. Slide sprockets off shaft.
SERVICE MANUAL· 1975 SCORPION BRUT SLIDE SUSPENSION 1. loosen spring adjusting eyebolts. Remove springs. 2. Remove cotter pin, castellated nut and cross bolt. Pull shock assembly out of slide assembly. (See Fig. 5-6). 3. Additional disassembly of the slide suspension may be accomplished by removing shafts which hold the: a. front idlers b. rear idlers c.
SERVICE MANUAL- 1975 SCORPION BRUT () FIG. 5-6 FIG. 5-7 FIG. 5-8 ASSEMBLY /INSTALLATION Assembly and installation is accomplished in reverse order of removal and disassembly. (_; 5·7.
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