SCORPION 1975 LIL' WHIP Service manual

( n

1975

Scorpion

Whip

Service Manual

Eng

ine Section

1 l

SERVICE MANUAL 1975 SCORPION WHIP

ENGINE SYSTEM

Functional Description:

2 -C YCLE ENGINE FUNDAMENTALS

The Rockwell 2-cycle air coo l ed ga s oline engine, p a rti cu larly th e axial fan cooled twin cy lin der e n gi n e, ha s become v er y popular to day for s nowmobil es. It i s uniquely qualified for this ap plication because of its high power output, li g ht weight and ease of lubri cat i o n, with few e r moving part s than other conventional 2-cycl e and 4-cycle e ngin es.

How e v e r, in order to get the best possible u se and ensure that it r e tain s it s high degree of d ependab ility and e nduranc e, it must receive pr oper care and maintenance. Th erefo re, it i s n ecess ary for u s t o know some thing about the basic fundam enta l s of this e ngin e and how it functions.

IN TAKE

OPERATION

The Rockwell 2-cycle Twin Cylind e r e ngine is of th e loop-s c av e nged third port type, the most widely used de s ign today. It u ses a mixtur e of gasoline, oil and air for combu s tion, lubrication and cooling . It fires on every stroke of each piston. Th ere are two power strokes for every revolution of th e crankshaft.

EXH/ UST

A s the piston moves upward in th e cylinder it draws the fuel/air mixture into the crankcase through the intake manifo l d whi l e at the same time compr ess ing fu e l that has b ee n forced into the combustion chamber. See Fig. 1 1 A.

As the piston near s top dead center the spar k C plug is fired and the compressed fuel/air mix' - - - - - - ---' ture burns and expands thereby forcing th e pi s ton downward on a power stroke.

As the downward stroke of the piston turn s th e crankshaft, it al so s tart s to compress th e fuel/air mixture in the crankcase and, simultaneously, op e ns th e exhaust port and closes the intake port. See Figs. 1-1 B & C.

FIG. 1 1

TRANSFER n

)

1 · 2

(

After the exhaust port is fully open and the in take port is fully c l osed, 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 m ost of th e burned ex h aust gases ha ve left the cy lind er, an incoming charge of fuel/air mixture scavenges the combustion area g ivin g it a fr esh charge and the cycle is then repeated.

See Fig. 1 1 D.

Because lubrication is dependent on the m 1 xmg of o il and fuel, it is extremely important that good quality o il and gaso lin e are properly mixed . The prope r ratio of oi l to gasol i ne w ill prevent possib l e engine overheating, piston or cy lin der scoring, or eventua l engine seizure .

Too much oil an d not enough qasoline can lead to incomplete combustion, fouled plugs, carbon bui ld up and muff l er clogging.

SERVICE MANUAL 1975 SCORP ION WHIP

1 3


EXHAUST SYSTEMS

SELECTION

Selection of an exhaust s y s tem (including exhaust manifold, interm e diat e pipes, e lbow s and muffler), is a r es ult of thorough te s t procedures involving m e asurem e nt of fu e l con sumption, hors epo w e r and noise level. Contrary to popular belief, the exhaust system is not only for quieting the engine, but al s o se rve s to in crease horsepow er output. Changes mad e to the original equipm e nt exhaust system by changing any component in th e s y stem can result in lo ss of power and/or severe e ngin e damage. For thes e r e a s ons, int e rmediate l e ngth s of pipe betweeen the cylinder and th e muffler ar e particularly critical.

TUNED MUFFLERS

Tun e d 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 cylinder a l lowing fuel and air to rapidly replace it and a l so "cram" over -sc avenged fu e l and air mixtur e fr o m the e xhaust pipe back into the cylinder u s i ng sound waves and sound energy. This is ac complished at the speed of sound which allow s the engine to produce h i gher torque at higher

RPMs.

D o n a l dso n

FIG. 1 2 l

(

Tuning

Co u r t esy o f Dona ld son Muf f l er Co

FIG. 1-3

1-4

SERVICE MANUAL 1975 SCORP ION WHIP

DESCRIPTION

TABLE OF SPECIFICATIONS

ENGINE MOD EL

2F 340-6 2F 400 8

BORE

2 .

362"

(60 mm)

2.559"

( 65.0mm)

-

S TROKE

2.362"

(60mm)

DISPLACEMENT IN cc 338 398

COMPRESSION

IGNITION SYSTEM

LIGHTING COIL VOLT AGE AND

OUTPUT

*TIM IN G BEFORE TDC (CENTRIFUGAL

WEIGHT ADVANCED)

TIMING BEFORE TDC (CENTRIFUGAL

WEIGHT RETARDED)

BREAKER POINT GAP

SPARK PLUG THREAD

SPARK

RATION (actual)

PLUG GAP

.0 1

1 2: 1 1 2: 1

Bosch Flywheel Magneto

1 2:1

12V-150W

. 1 02 . 1 1 2

8" to .020" .

12V 150W

.

102.

018" to

112

.020"

.014"to.016

"

.0

2F 440-9

.

2 .

658 "

(67.5mm)

428

12V 1 50W

1 02 -

18" to

. 1 1

.0

.020

"

(0.5mm.)

14mm. x 1 .25- 3 / 4 " reach

.020"

(0.5mm.)

.

020 "

(0.

5mm .

)

2

20"

SPARK PLUG-BOSCH (ORIGINAL

EQUIPMENT)

TYPE OF ENGINE COOLING

N 3 N-3 N-3

ROTATION OF CRANKSHAFT

CARBURETOR

Axial Flow Fan

Counterclockwise (PTO s ide)

.

Walbro W F

FUE L/OIL RATIO

As Specified on Scorpion Oil Container

GASO LINE 95 octane, minimum (lead free not acceptable)

TYPE OF OIL Specia l 2-Cycle Snowmobile Oil

* Do not exceed indic ated advance, as this will result in severe engme damage. l 6

(

(

TORQUE SPECIFICATIONS

CYLINDER HEAD NUTS


TABLE OF SPECIFICATIONS

340-6 400-8 440-9

28 32 Ft .

-Lb. 1 6-1 8 Ft. Lbs.

CYLINDER BASE NUTS

16-18Ft.-Lbs.

FLYWHEEL NUT

44-50 Ft.

Lbs.

INTAK E MANIFOLD NUTS 16-18 Ft.

Lbs.

FAN HOUSING SCREWS 16-18Ft.-Lbs.

22 24 Ft.- Lbs. FAN WHEEL NUT

RING GEAR SCREWS (6mm.)

6-7Ft.Lbs .

RING GEAR SCREWS (8mm.) 10 12Ft.-Lbs.

Tightening Sequence for Cylinder Base Nuts

All Models

0 0 8 8

PTO SIDE

0 0 0 8

Tightening Sequence for:

Cylinder Head Nuts, Fan Housing, Ring Gear Flange, Intake Manifold and Recoil Starter Clamps

0

0 0

400-8

440-9

®

340-6

0

8 0 CD

0

0

1 7

SERVICE MANUAL- 1975 SCORPION WHIP

ROCKWELL TWIN CYLINDER ENGINES

MODELS 2F-400-8

DISASSEMBLY

2F-440-9

A. Recoil Starter

Remove four (4) screws holding the recoil assembly to the fan housing.

See Fig. l 4.

See pages l-28 A, B, C for recoil starter disassembly.

(

FIG. 1-4

FIG. 1-5

)

B. Lower Fan Pulley and Carrier Assembly

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

) l 8

(

C. Upper Fan Belt Pulley Assembly.

Insert a 3/16" drill or a suitable punch through the indexing hole into the im-· peller body. With a 17 mm so cket wrench, remove the fan nut, lock washer, pulley halves and spacers. See

Figs.1-7, 1-8,1-9.

SERVICE MANUAL - 1975 SCORPION WHIP

FIG. 1-7

FIG. 1-8

F I G . 1 -9 l 9


D. Flywheel Magneto

Remove the crankshaft nut using a 27 mm socket wrench. Pull the flywheel by attaching flywheel puller 444-31-843 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. 1-10

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. l-10

FIG. 1-13

)

E. Intake Manifold Assembly

Remove t he four (4) intake manifo l d nuts and washers. Remove manifold assembly and insulators. See Figs. 1 14 ,

1-1 5.

SERV I CE MANUAL 1975 S CORPI O N W H I P

FIG. 1 14

FIG. 1 15

] .

] ]


F. Fan Housing and Armature Plate Assemb ly

R e m o ve scre w h o ld ing s park plug wire bracket t o fan housing. With a socke t type 5 mm Allen wrench and impact driver, r e move th e four (4) mounting bolts holding fan housing to crankcase. (See Fig. 1 16) .

Remove fan hou s ing from cran kca se (See

Fig . 1 17).

(

FIG. 1-16

(

Unplug connec t or hou sing c oil wire s . (Note color coding of wires.) R e move armature plate assembly and wire s , a s a unit, from fan h o using .

1 -1 2

FIG. 1-17

(

r

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 furthest bearing in the housing. See Figs. 1-18,

1-19, 1 20.


FIG. 1-18

(

FIG. 1 19

(

'

FIG. 1 -2 0

1 13

G . R e move spark plug s with spark plug wrench. (See Fig. 1 -2 1.)

H. Cy li nder Heads

Remove cylinder head nut s with a

13 mm socket wrench. Mark cy li nder h eads before removal from cy lin der .

Remove and discard gaskets. See Fig.

1-22.

I. Cy lind ers

Remove the eig ht (8) cy lind er base nuts using a 13 mm socket wrench and remove the eight (8) spring washers.

The cylinders may b e removed. See

Fig . 1 23.

NOTE: I M P 0 R T A N T

If removal of cylinders only is required, care mu s t be taken that the crankcase seal is not disturbed. The removal of the PTO cylinder will allow the placement of two bolts and nut s with flat washers to app ly constant pressure to crankcase assembly. Bolt s s hould be placed in the center two holes (adja ce nt to the fan side cylinder). See Fi g. 1 31. The second cylinder may now be removed.

SERVICE MANUAL - 1975 SCORPION WHIP l

'{_} '\

,,

~ '

' '

. _ ; /

FIG. 1 21

FIG. 1-22

J " f\G. 1-23 r )

1 14

J. Piston and Wri st Pin

With needle nose p l iers, remove circlips from pistons. 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.

K. To separate the crankcase halve s, hold upper portion of crankcase assemb l y in one hand, lifting slightly and tap the end of the crankcase with a soft hammer. The crankcase wi ll separate and the crankcase may be removed. See Fig. 1 24.


I

~ I

FIG. 1 -24 l 1 5

SERVICE MANUAL- 1975 SCORPION WHIP

L. 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

/

)

1-16

SERVICE MANUAL • 1975 SCORPION WHIP

ASSEMBLY

A. Crankshaft Bearings.

Heat crankshaft bearing s in oi l (or oven) to approximately 180 d eg rees .

Slide bearing on crankshaft.

B. Crankcase.

Inspect and c l ean both halves of crankcase.

The proper sealant material such as Permatex Hy Tack Spray should be now sprayed on crankcase sea ling surfaces. See Fig. 1-29.

Before installing crankshaft into crankcase low er half of it will be necessary that all bearing outer surfaces be wiped clean of foreign material so that proper sealing will occur. After installing PTO thrust washer and oil sea l (inside groove of oil sea l 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 sea l i s lined up with the crankcase split lin e.

BEARING_j t

Tap upper crankcase half to seat with lower half .

FIG. 1-28 t t

I

L-SEAL

-BEARING

FIG. 1-29

\

~

-

-

FIG. 1-30

1-17


Install lwo crankcase holding bolts in the center holes of the PTO side of crankcase.

(Fig. 1-31) Tighten finger tight.

C. Piston, Cylinder and Cylinder Heads

The pistons must be clean and free from carbon 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. 1-31

(

'

.

:

'~

11

I

FIG. 1-32

CIRCLIP OPENING HERE---'

FIG. 1-33

1 18

(

1. Oil the piston pin end bearings.

2. Install one circlip in piston.

3. Heat the piston sufficiently to allow pin to push into piston and install pin.

4. Install second circlip. (See Fig. 1-33 for correct orientation of circlips.)


0

FIG. 1-34

FIG. 1-35 l-19


In sta ll base gaskets on th e cylinder studs and position aga i nst the cylinder flanges ( see Fig.

1 36). With the use of a ring compressor , l ower cylinders one at a time over th e pistons. Install base washers and nuts finger tight. See Fig. 1 -37, 1 38.

Temporari ly in s tall the intake manifold without gaskets and tighten manifo ld nuts to sixteen (16) to eig hteen (18) foot pounds.

See Fig . 1 39. Cylinder base nut s may now be torqued to sixteen (16) to eighteen (18) f oo t pounds as outlined on spec ification page.

The proper piston h e ight can be measured at the top of the cylinder. The edge of the crown of the piston mus t not protrude above the top of the cy l inder with the p i s ton in th e top dead cen t e r position. If the piston does protrude above the cylinder , a thicker ba se gasket must be used. See specifica tion page for dimensions and color cod ing . It is important that only one cylin der at a tim e be ad j usted or the crankcase will separa te and lose it's seal.

~ l

FIG. 1-36

FIG. 1-37

FIG. 1-38

I

1 20

(

Oil cy lind ers 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 pounds. (See Fig. 1 40).

NOTE: The head gaske t for th e 400 cc engine has an additional hole in it to distinquish it from the 440 cc gasket.


FIG. 1-39

FIG. 1-40 l -2 1

l 22


D. Fan Housing and Impeller Bearings

Clean fan shaft hub. Install circlips and spacer. Use grease to hold spacer in place.

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 l i

1 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 down screws, washers, and lockwashers. See

Fig. 1-42.

Place fan housing assembly over crankshaft and position to crankcase assembly . Install 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

( r

J

FIG. 1-41

)

)

SERVICE MANUAL· 1975 SCORPION WHIP

Torque to sixteen (16) to eighteen (18) foot pounds. Connect ignition wires to external ignition coil and to connector housing. Check ground wire s for proper position. Install ignition cable bracket to fan housing.

F. Intake Manifold

Install spacers, gaskets and intake manifold

(Fig. 1 -44 ) . Torqu e nuts evenly to six teen

( 16) to ( 18) foot pounds.

G. Upper Fan Pulley As se mbly

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. oo

0 0

H. Flywheel Assembly

Check advance mechanism for free operation, lubricate inside cam surface

(Grooved area). Slide assembly over crankshaft and align key ways.

F I G. 1-44

1 23


Instal l 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 add i ng 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.

FIG. 1-46

FIG. 1-47

.

_

....

~

FIG. 1-48 l-2 4


RECOIL STARTER

Disassembly

(See Fig. 1-49 for recoil start breakdown, and Fig.

1-50 for Recoil Starter Assembly .

)

1. Remove retaining nut (11), spring washer

(12) and Thrust washer (8) from threaded shaft of reel hub. (Fig. 1-51).

2. Manipulate friction plate (4) on reel hub until eye end of return spring (9) aligns with retaining slot. Remove friction plate. (Fig. 1-

52, 1 53).

3. Remove the three pawls (3), (Fig. 1-54) .

4. 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.

5. Unwind the rope; lift and untie the knotted end from center hub of reel, remove reel (2).

(Fig. 1 55).

6. 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).

12 8 21 4 9 6 7 3 2 10 18 19 20

Recoi I Starter

14 3 14 13 3 5

FIG. 1-49 l 25

SERVICE MANUAL 1975 SCORPION WHIP

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. l-26

FIG. 1-52

(

FIG. 1-50

(

)

FIG. 1-51

Q "'_,

( ) ,, · , .

!'. f)

"

FIG. 1-53

\ I

)

FIG.

1

54

SERVICE MANUAL - 1975 SCORPION WHIP

~ l -

FIG.

1-55

FIG. 1-56

1 27


Assembly

1. Replace defective parts.

2 . Install main spring as follows: a. Secure main s pring winding tool, part number 43 0797-60, or equ ivalent tool, circular end up, in a suitable bench vise . b. Start with the long rolled end of main spring (5) and wind spri ng into circular end of tool in a clockwi se dire c tion. (Fig.

1-57)

0 c. Remov e tool from vi se. Grasp th e tool by its handle and lower th e tool , with spring in s talled, into case (1) (Fig . 1-58). d . Secure the long roll ed end of spring over the fix e d spring retaining pin . (Fig . 1-

59). Remove winding tool (Fig . 1-60) .

Apply a light film of Lubriplate, or equivalent, to spr i ng.

3. Secure case, open side up, in bench vise .

4. Tie a knot at one end of the rop e . Secure knott e d e nd in th e center of reel (2) . Pull rope taut and wind e ntire rope around reel in an anti-clockwise dir e ction until th e free end protrudes through the notched sec tion of th e 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 engages with the free end of main spring. Ten sion will be felt when reel and spring are properly engaged. (Fig. 1-61, 1-62).

6. Rotate reel a maximum o f three com pl ete 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. In stall cup washer (7) flat s ide down, spring

(6) and return s pring. Ensure that plain end of return spring is properly engaged in the retaining hole in reel hub.

1 28

FIG. 1-59

FIG. 1 57

(

FIG. 1-58

(

(

9. Install friction plate (5) over reel hub.

Manipulate plate until eye end of return spring engages and locks crosswise in retaining slot.

10. Rotate friction plate unti I the three notches are aligned with pawls when pawls are at the recoil position.

11. Install flatwasher (8). lockwasher (12) and nut (11 ). Tighten nut securely.

12. Untie the temporary knot in free end of rope and install the rope handle. Tie a permanent knot and fit handle securely.

13. 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 direction. Clockwise installation on the winding tool is necessary to ensure correct anticlockwise installation of the spring when tool is placed upside down in the case.

SERVICE MANUAL · 1975 SCORPION WHIP

FIG. 1-60

FIG. 1·61

FIG. 1·62

(

FIG. 1·63 l-29


TIMING PROCEDURE

NOTE: Recoil starter, carrier, lower pulley assembly 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 ground. Attach positive lead of ohmmeter to

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 position observed through opening in flywheel.

Check gap with wire gauge and adjust to

.015 if necessary. See Fig. 1 66.

FIG. 1-64

FIG. 1-65

)

FIG. 1-66

)

1-30

D. Rotate flywheel counterc l ockwise to top dead center and adjust dial to zero. Place selector knob on ohmmeter to R x 1. Ohmmeter needle will indicate a closed circuit.

See Fig. 1 67.

SER VICE MANUAL· 1975 SCORPION W H I P

FIG. 1 67

Move the centrifugal weights in flywheel to the full advanced position. See Fig. 1-68.

I

I

I

} i

FIG. 1 -68

Rotate flywheel counterclockwise one complete revolution to between .1 02 and . 112.

See Fig. 1-69.

F I G. 1 -69 l-31


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 armature 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 illustration.

E. 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 flywheel counterclockwise while watching dial indicator.

The needle must make one full revolution and stop at between .1 02 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.

1-32

F

I

G.

1-70

(

FIG.

1-71

(

(

(

(

TROUBLE

Manual starter rope comes out but pawls don't engage.


TROUBLE SHOOTING CHART

PROBABLE CAUSE

1. Lack of friction plate return spring action.

2. Defective pawls.

REMEDY

1. Check friction plate returnspring. Replace as required.

2. Check for broken or bent pawls. Replace pawls as required.

Manual starter rope doe sn 't return.

1. Recoil spring broken or bent.

2. Pulley housing warped or bent.

3. Starting pulley worn.

Electric starter inoperative.

Hard to start or won't start .

1. Replace spring.

2. Replace housing.

3. Replace pulley.

1. Loose electrical connections.

2. Poor ground.

3. Faulty battery or circuits.

4. Faulty electric starter.

1. Retighten connections.

2. Secure ground connection.

3. Check, recharge or replace battery.

4. Check starte r solenoid.

Repair or replace.

5. Inspect starter motor for evidence of moisture and broken or worn brushes. Dry out as necessary.

6. Check starter switch . Replace if required.

7. Check harness or connector for broken wire. Repair or re place.

1. Inoperative diaphragm or inlet check valve.

2. Fuel enrichening valve not not pulled up to start.

1. Refer to Carburetor

Section.

2. Ensure enrichening valve is pulled up.

3. Spark plugs improperly gapped, dirty or broken.

4. Magneto breaker points improperly gapped or dirty.

5. Head gasket blown or leaking.

6. Empty gas tank or improper fuel mixture.

7. Water in fuel system.

8. Weak coil or condenser .

9. Obstructed fuel system .

3. Remove plugs. Clean, adjust or install new plugs.

4 . Clean, ad ju st or replace points.

5. Replace gasket.

6. Refill tank with specified fuel/oil mixture.

7. Drain fuel from carburetor.

Add carburetor de-icer as re qui red to fuel.

8. Replace faulty coil or condenser.

9. Disconnect fuel lines.Clear obstruction . Flush system. Connect fuel lines.

1-33


TROUBLE


(coNr.)

PROBABLE CAUSE

10. Air leak in crankcase or inlet system.

1 1. Primary wire broken.

12. Engine not timed properly.

REMEDY

1 0. Check crankcase pressure

(3-6 PSIG)

11. Repair or replace primary wire.

12. Re-time engine.

13. Secondary wire not connected or spark plug protector not installed properly.

13. Secure secondary wire or spark plug protector.

Impossible to adjust idle.

1. Spark retarding mechanism not working properly.

2. Pistons or rings worn.

3. Faulty carburetor.

1. Repair retard mechanism.

2. Replace as necessary.

3. Check carburetor, check valve.

Refer to Carburetor

Section.

Mi ss ing at l ow speed or won't idl e s moothly or slowly.

1.

Incorr ect carburetor idle adjustment.

2. Spark plugs improperly gapped or dirty.

3 . Head gasket blown or l ea king .

4. Loo se or broken magneto wir es.

5. Magneto br ea ker points improperly gapped or dirty .

6. Weak coil or condens er.

7 . Improper fu e l mixture .

(1) Too much oil

(2) Too littl e oil

8. L ea king cra nk s haft se al.

1.

2.

3.

Adjust idle-Refer to

Carburetor Section.

Clean, adjust or install new plugs.

Replace gasket.

4. Repair or replace wires.

5. Adjust, clean or install new points.

6.

7.

Replace coil or condenser.

Refuel, using specified fuel/oil mixture.

8. Replace seal.

)

)

Missin g at high speed or int ermitten t spar k.

1. Spark plug s improp e rly gapped or dirty .

2. L oose or broken magneto wir es.

3. Magn e to br ea ker points improp e rly ga pped or dirty.

4. W ea k coil or condenser.

5. H ea t rang e of spark plug incorrect.

6. Leaking h ea d gasket.

7. Engine improperly timed.

1.

2.

Clean, adjust or install new plugs.

Repair or replace wires.

3.

4.

5.

Clean, adjust or install new points.

Replace coil or condenser.

Install specified spark plugs.

6.

7.

Replace head gasket.

Re time engine.

1-34

)

) TROUBLE

Coughs, spi t s, slows down, surges



PROBABLE CAUSE REMEDY

1. Idle or high speed jets too lean .

2. Leaking gasket flange.

3 . Inlet control level set too low .

4. Pulsation line obstructed.

5. Fuel pump not supplying enough fuel due to :

( 1) Punctured diaphragm.

(2) Inoperative inlet check valve.

1. to 5.

Adjust carburetor. Refer

Carburetor Section.

6. Reseal crankcase.

6. Crankcase not properly sealed.

7. Idl e or main carburetor noz z le obstructed.

8. Fuel line obstructed.

9. Carburetor inlet needle and seat obstructed.


Section.

8. Remove fuel lin e. Clear obstruction. Replace line.


Section. to

Overheating 1. Carburetor too lean.

2. Carburetor too rich.

3. In correct timing.

4. Too much carbon.

5. Spark plug too hot.

6. Engine fan belt loose or broken .

7. Air l ea k in manifold.

8. Crankcas e seal l ea king.

1. and 2. Adjust carburetor.

Refer to Carburetor Section .

3. Retime engine to Specifications.

4. Remove cylinder heads. Clean top of pistons and inside compression chamber. Clean out exhaust port.

5. Install specified spark plugs .

6. Replace or adjust.

7. Tighten nuts or change gaskets.

8. Fit new seal.

Vibrates excessively or runs rough and smokes.

1. Idle n eed carburetor l

2. Enrichening e jet or high too rich. valve not speed 1 to 4. Adjust needle or change jet. Refer to Carburetor Sec operat ing properly (bent linkage).

tion.

3. Float lev e r too high . (carbur etor floods).

4. Air bleed plugged.

5 . Muffl e r obstructed.

6 . Engine not secured tightly

5. Check and dear muffler.

6. Tighten engine mounting to e ngin e support.

7 . Wat er in gas. bolts.

7. Add carburetor de-ice fluid as required.

1-3 5



TROUBLE

Won't start, kicks back and backfires.

PROBABLE

CAUSE

1. Spark plug wires reversed.

2. Flywheel key missing or sheared.

3. Faulty condenser.

4. Improper timing.

5. Faulty breaker points.

6. Unhooked spark retarding mechanismor spring broken .

REMEDY l. Install wi're correctly.

2. Replace key.

3. Replace condenser.

4. Re-time engine.

5. Adjust or replace points.

6. Reconnect mechanism or replace spring.

No acceleration, low top R.P .M., hard to start.

Good spark but engine runs on one cylinder.

No acceleration. Idles well but dies down when put to full throttle .

1. Spark plugs improperly gapped or dirty.

2. Magneto breaker points improperly gapped or

1. Clean, adjust or install new plugs.

2. Clean, adjust or install new points. dirty .

3. Faulty coil or condenser.

4. Loose or broken magneto

3.

4.

Replace coil or condenser .

Repair or replace magneto wires.

7. Crankcase leaking. wires.

5. Blown head gasket. 5. Replace head gasket.

6. Float lever adjustment too 6. Refer to high. Carburetor Section.

7. Install new seal.

8. Main (high speed) jet t0o rich. 8. Change jet.

1. Leaking cylinder head.

2. Magneto wires broken inside (coil ground broken).

3. Cracked cylinder wall.

4. Defective spark plug.

5. Breaker points improperly gapped.

6. Crankcase seal leaking.

1. Check head for warps, cracks.

Install new gask e t and cylinder head.

2. Repair or replace wires.

3. Replace faulty cylinder.

4. Clean, adju.;t or install new plug.

5. Re-adjust points.

1. Low speed needle set too lean.

2. Dirt behind needle and seat.

3. High speed jet obstructed.

4. Float lever set too low .

5. Silencer obstructed.

6. Fuel pump not supplying enough fuel due to:

(1) Punctured diaphragm

(2) Non-functioning check valves.

7. Fuel line obstructed.

6. Install new seal.

1. to 6.

Adjust carburetor.

Refer to Carburetor

Section.

8. Not enough oil in gas.

9. Breaker points improperly gapped or dirty.

10. Engine improperly timed.

7. Remove fuel line. Clear obstruction . Replace line.

8. Refuel, using specified fuel / oil mixture .

9 . Adjust, clean or install new points.

10. Re-time engine to specifications.

1 36

(

(

TROUBLE

No power under heavy load.


TRO · UBLE SHOOTING CHART

PROBABLE CAUSE l. Magneto breaker points improperly gapped or dirty .

2. Ignition timing too far advanced.

3. Magneto coil plate loo se.

REMEDY l. Clean, adjust or install new points.

2. Adjust timing.

3. Check magneto and secure coil plate.

Cranks over extremely easy on one or both cylinders.

Loss of compression.

1. Scored piston.

2. Blown head gasket.

3. Loo se spark plug.

4. H ead bolts not tight .

1. Replace faulty piston.

2. Replace head gasket.

3. Check plug for security.

4. Torque head bolts to proper specifications.

(

Engine won't crank over. Unable to rotat e flywheel. l. Piston rusted to cylinder wall.

2. Crankshaft seized to bearing . (main or rod)

3. Broken connecting rod.

4. Flywheel seized t o coil plate.

5. Engine improperly assembled after repair. l. Remove piston and cylinder.

Replace defective parts .

2. & 3. Disassemble engine.

Replace defective parts.

4. Remove flywheel. Replace defective parts.

5. Recheck re-assembly procedure .

( l -37

J

'

: )

I

I

(

1975

Scorpion

.

Whip

Service Manual

Carburetor

Section

2 1



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 engine crankcase through the impulse line, actuate the carburetor fuel pump to move the fuel from the fuel tank into the carburetor. The fuel level in the car buretor fuel reservoir is maintained by a float-controlled needle valve that opens as the level drops and closes as the fuel rises to a specific level. The engine fuel demand determines the air flow through the carburetor throttle bore. The air flow rate varies the pressure differential on the fuel in the reservoir. This pressure differential forces fuel into the throttle bore through one or more openings depending upon the operational phase of the engine.

(

)

_)

2-2

)

SERVICE MANUAL 197 5 SCORPION WHIP

The function of each element of the carburetor is described below. (See Fig. 2-1 ).

1. Engine Impulse: Actuates fuel' pump diaphragm with alternating pressurevacuum pulses from engine revolutions.

2. Fuel Pump Diaphragm: Fluctuates in response to engine impulse. Draws fuel into surge chamber with upward, vacuum stroke, of engine piston .

Pushes fuel with pressure downward stroke of engine piston, through outlet check valve.

3. Fuel Inlet Fitting: Fuel drawn through line from tank .

4. Fuel Channel: Fuel is routed into surge chamber.

5. Surge Chamber: Fuel accumulates waiting for inlet check valve to open for passage a t engine piston down stroke.

6. Surge Diaphragm: Reciprocates with pump diaphragm balancing to at mospheric pressure, cushions pulsations.

7. Leaf Spring: Assists pump diaphragm when engine impulses are weak at starting and idle c ir cui t s.

8. Inl et Check Valve: When opened by engine vacuum, allows fuel passag ' e from surge chamber into pump chamber, feeding to outlet check valve.

9. Outlet Check Valve: Opened by engine pressure pulse forcing fuel down through inl et valve needle passage.

10. Fuel Channel: Routes fuel to inlet needle valve .

11. Filter Screen: Fuel is filtered before fed into inlet needle valve. Cleanse screen when servicing by flushing or air stream.

12. Inlet Valve Seat: Hole through which fuel feeds when needle valve drops s lightly away.

13. Inlet Needle Valv e: As float rises it pushes valve into seat closing off fuel passage. When float drops, needle opens hole in seat allowing fuel to flow i nto bowl reservoir.

14. L ever: Raises and lowers with float to activate inlet needle valve .

15. Float: Raises and l owers to maintain fuel level as fuel is used.

16. Fuel Bowl Reservoir: Constant level of fuel stored and maintained by float action on l ever to open and close inlet needle valve.

2 3


The four operationa l phases of the Walbro F l oat Carburetor used on the 1975 Whip are:

( 1) Starting 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 ap pearance.

FIG. 2 1

COLOR CODE

St

a

rting Circuit

A. Enrichment Valve: : In operation when control lever, is up (vertical). elimates choke. Like opening a faucet an extra column of fuel is introduced through the valve into carburetor bore as engine is cranked; offering easier, quicker starts. This valve may be left open until engine is warm.

B. Thrott l e Valve: Must be at idle position freeing both hands for starting. Required air is drawn in through the air bleed ports mixing with the fuel.

C. Start & Idle Fuel Feed Tube: Fuel is drawn by engine vacuum up tube, through part throttle passage into

Enrichment Valve and id l e circuit.

D. Enric h ener & Id l e Feed Ports: Tube picks up at these two pockets for starting full vo l ume.

E. Air Bleeds: Vacuum draws in air at these four points to mix with fuel in metered ratio.

F. Enric h ener Port: Fuel and air mixture flows into throttle bore when enrichener valve i s open .

G. Id l e Need l e: Fuel is a l so drawn through the idle needle circuit which is pre-set for the idle position.

H. Id l e !Feed Hole: Additional fuel is dischar~ed f rom th i s por t into th r ott l e bore for starting.

Air

Crankcase

I mpulse Air

2 4

SERVICE MANUAL · 197 5 SCORPION WHIP

Idle Speed Circuit

c

FIG. 2-2

1 . Throttle Va l ve: Remains closed, air being drawn t hr ough Idle Air Vent.

2. Enrichment Valve: C l osed as engine warms.

3. Fuel Idle Needle: As engine requires, needle is turned in t o l ean mixture or turned out to a ll ow grea t e r fuel flow (like a water f auce t) .

During break-in, ope n l

1/2 t urns the n c l ose about 1

/2 turn a fter break -i n.

4 . Idle Air Vent : Engine vacu um draws ai r through thi s interchangeable fix ed j et as we ll as through th e part thr ott l e progress i on holes.

5. Fuel Idle Passage: Al l fuel f or id ling is drawn through this passage . The fl ow can b e adju sted by th e Fu e l I d l e N eedle.

2 -5

SERV I CE MANUAl. 19 75 SCORPIO N WHIP

Par Throt

tl

1. Throttle Valv e: Fuel i s being f ed th rough id l e circui t . As th e Throttle Va l ve is opened a series of three holes is ex posed progressively offering smoo th acce l eration as they in crease fuel f l ow.

2. Part Throttle Ho l es: Three h o l es are sk illfully located and carefu ll y sized to feed measured fue l drawn by vacuum as each hole i s allowed to flow wit h open in g of the Th rott l e Va l ve.

3 . Venturi: Thi s acts as a restric ti o n to the air rushing th rough the carbu r e t o r bore int o the engine to fil l th e vacuum l eft by the piston move m ent. As th e air velocity increases at the ven turi the pressure is dropped according to the d egree Th ro t tle Va l ve is opened. As t he Part Throttle holes are ex p osed to the dr op in pressure, fuel rush es in t o he l p bring the air pressure u p . The Idle Feed h o l e continues to f l ow for th e same reaso n .

4. Air i s also fed by th e Idle Air Ve1111i Jet, a ffect i ng the v acu um w h ich lifts fu e l up the feed t ube. A smaller jet de l ivers less a i r, and the ref ore a richer m ix ture, especially at "early" part throttle.

2 6

FIG. 2-3


High Speed Circuit

1. Throttle Valve: Valve is wide open to allow full air and fuel flow, metered to contro l top engine speed.

2. Main Fue l Nozzle: As the throttle opens, air velocity increases through the venturi and the resultant vacuum draws fuel from the main nozzle.

3. High Speed Fixed Jet: Fuel is fed to the fixed jet hole from the bow l reservoir. The hole may be varied in size by exchanging the jet on which sizes are stamped. Larger engines require larger jet holes for greater fuel consumption. Too large creates a rich mixture, too small a dangerous lean mixture.

Note: High altitudes require a smaller jet to compensate for the thinner air.

Note: Air Intake Silencer: Regulations require the noise created by air rushing into the carburetor be reduced to a minimum. All

WF models are finely calibrated in tune with original equipment Silencers, both Intake and Exhaust . Anytime the characteristics of either are changed or removed a risk of burning out an engine exists and Warranty is void .

FIG. 2·4

2-7

Carburetor Disassemb~y

Fuel Pump and Gaskets

1. Remove four (4) mounting screws. (See

FIG.2-5). _ ·• , .. · , .

. ""'1-

.;.~:~ ~

2. Lay out part~ i Q.§ ~~~:~:~n<;~ shGwn in FIG .

2-6. Do not · remove nJbb er ' fuel pump valve~ unl · ess , replacements are

, ., , available. . . , •.. ' ··, .

~' ~;.;>

.

~

3. In spect all parts, opE}nmgs, needles, valves, valve seats and ,•i any oth~r functioning part Jor , clogg j' ng or qamag e.

(See Fig. 2 7) .

~ · · •

4. Clean por t s with a mild so lv ent or regular fuel mixture. Repair or re:place

.'::~" parts as n ' ecessary.

. - - - - M O UNTIN G SCREWS (4}

WF 10

340

WF-11

400,440

(

J til

G

F

B

FIG. 2-6

D C

_

..

FIG. 2-5

HIGH SPEED FUEL JET

A

E

FUEL

INLET

A. Fuel pump cover assembly

B.

Fuel pump leaf spring c.

Pump gasket

D.

Pump diaphragm

E.

Fu e l pump body assembly

F . Surge chamber diaphragm

G. Surge chamber gasket

H. Throttle bracket plate

I. Fuel pump to body gasket

J . Idl e Fuel feed tube

(Also see FIG . 2-13)

K. Carburetor body assembly with float bowl assembly

)

J


(

PARTTHROTTLE-----'-

HOLES

ENRICHENER

PORT

)

Fuel Bowl and Gasket

1. Remove four (4) mounting screws. (See FIG.

2-8)

2. Lay out parts sequentially as shown in FIG. 2-

9.

3. Check all parts openings, valves, valve seats and other functioning parts for clogging or damage . Clean, repair and replace as necessary.

4. Clean parts with a mild solvent or regular fu e l mixture. Clean all sediment from the bottom of t'he bowl. Remove the main jet and idle feed tube . Blow air through the idle feed circuitry and main air bleed circuit.

~------------FUEL CHANNEL-SURGE

CHAMBER TO NEEDLE VALVE

FIG. 2-7

FUEL ENRICHENER

VALVE LEVER

MOUNTING

SCREWS {4)

FIG. 2-8

2 9


MAIN AIR JET

Carburetor Reassembly

1. Reassemble in reverse process of disassembly. Install components on top of the carburetor first followed by the float bowl assembly.

2. Specific care should be exercised in the following areas: a. The fuel pump leaf spring should be flat to center between the two castings when seated. b. Car e fully position the idle feed tube and tube pressure spring. c . During installation, wind the float support spring 1/2 turn from rest position for correct loading. (See FIG. 2-1 0) d. Slide the fuel bowl gently over the point of the idl e feed tube. A slight tension against the tub e pressure spring should be felt just before the bowl s e ats on its gasket.

FIG. 2-9

FUEL BOWL GASKET

FUEL BOWL ASSEMBLY

FLOAT SUPPORT

FLOATS

FIG. 2-10

FLOAT VALVE

LEVER u

FIG. 2-11

2 10

(

Adiustments

l . IDLE FUEL The idle needle (See FIG. 2 8) is usually set one ( l) turn open. The set ting will vary with operator preference or changing conditions.

2. HIGH SPEED FUEL The fuel supply is limited by a fixed high speed jet. (See

FIG. 2 6) The jets ore available in various sizes and the optimum size used will depend upon temperature, altitude, etc. A smaller jet permits less fuel flow.

3. FLOAT With fuel bowl removed, and float assembly in place, turn the body costing upside-down so that float assembly is at top. Sight a l ong uppermost sur face of float and adjust by bending metering lever so that top surface of float is 1 1 /16" above body costing surface. (See FIG. 2-12) Adjustment may also be accomplished using the special tool available for this purpose. (See FIG.

2-13)

( )


BEND THIS LEVER TO ADJUST

FLOAT HEIGHT IF NECESSARY. t

1 1/16"

FIG. 2-12

L IDLE FUEL FEED TUBE

FLOAT ADJUSTMENT

GAUGE

( J

FIG. 2-13

2-ll

I )

( )

' -

).

~)

1975

Scorpion

Whip

Service Manual

Electrical

Section

3 1

SERV I CE MANUAL197 5 SCORPION WHIP

ELECTRICAL SYSTEM

The Scorpion Whip Snowmobile Electrical System is divided into four ( 4) subdivisions :

A. Power Generation

B. Ignition

C.

Voltage Regulation

D. Electrical Contro

l

and

Dis

tri

bution

LIGHTING COILS

POWER GENERATION


Electrical AC power , used for lighting and t ac h o meter operation is generated by rotating a per manent l y magnetized flywheel around two sta ti onary coi I s ( 1-1 20 watt and 1 23 watt) . The no l oad vo l tage increases with engine RPM and could reach 32 volts RMS. To maintain th e voltage at the requi r ed system level (13 14 vo lt s). an external vo l tage regulator is utilized . (See VOLTAGE

REG UL ATIO N )

MAIN

ELEMENTS:

1. Magnetic Flywheel

2 . 120 watt co il (mounted on stator plate)

3 . 23 watt coi l (mounted on stator plate)

-

FIG . 3 2

FIG. 3 1 POWER GENERA TI ON SCHEMA Tk

3-2

E N G I N E

CO NN ECTOR

FIG . 3-3


IGNITION


(See SCHEMATIC FIG. 3-8)

Rockwell engines are equipped with a flywheel magneto type ignition . An electrical current is generated by rotating a permanently magnetized flywheel about the ignition coil. The current initiated in this coil in turn energizes the primary coi l s of the external ignition coils. The secondary coils of the external ignition co i ls are situated in the force field generated by the primary coils.

When the points close, causing an interruption of the current flow through the pr i mary winding, its force field immediately co ll apses and generates a very high voltage in the second coil. This voltage in the region of severa l thousand volts wil l 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 generated current to reduce the tendency to overload the points . As soon as the voltage l evel in the primary winding drops be l ow that of the condenser, current again f l ows 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 .

.SPARK PLUGS

\ '

"

ENGINE

CONNECTOR

FIG. 3 5

MAIN

ELEMENTS:

1 . lg n ition Co i I (Stator)

2. Condensers (2)

3. Breaker Points (2)

4 . Ignition Coi l s (External) (2)

5 . Spark Plugs (2)

FIG. 3 6

3-3

SERVICE MANUAl 1975 SCORPiON W II?

SEE ENGINE DISASSEMBLY

(SECTION l ) FOR FLYWH EEL

AND STA TOR REMOVAL

~G !T~ON COIL (STATOR)

FIG . 3-7

CONDENSER

HI·

,..._.:11 ..

~

EXTIEIRNAl i G ITION COILS

3-4

ENGiNE CONNECTOR f i G. 3-8 IGNITiON SCHEMATIC

r - - - -

STATOR I GNITION COIL TO

E XTERNAl COIL CONNECTORS

SERVIC E MANUAL 1975 SCORPION WHIP

(

FIG. 3 9

EXTERNAL COIL

COIL TO SPARK PLUG LEAD

FIG . 3-10

•

EXTERNAL COIL

GROUND

3 5


VOLTAGE REGULATION

Functi

o

nal Description:

The voltage regulator is connected across th e lighting coils in parallel with th e electrical load of the s l ed. (Se e SCHEMATIC ELECTRICAL DISTRIBU-

TION AND CO NTROL FIG . 3-16). Under operating conditions, th e voltage drop acro ss the r egu lator is such th at approximately 13.8 V RMS is supplied to the snowmobile lighting circu it. Two typ es of regulat o rs are described in thi s section .

NORMAL LIGHTING COIL VOLTAGE

~

+ I

ALTERATION OF VOLT AGE

WAVE WHEN SCR

CONDUCTS

~0 ~~~~~~~~~~~---------

~,

Scorpion P

IN 043299

( Se e FIGs. 311, 3 1 2 and 3-1 3)

FIGURE 3-11

MAIN ELEMENTS:

1 . Si Ii con Contro l Rectifier (SCR)

2. Resistors (R 1, R2, R3, R4, Trim)

3. Condenser (C 1)

4. Diodes (CR 1, CR2, CR3, CR4 )

5. Tran s istors (Z1, Q1)

TIME

This so lid state regulator is al s o a shunt typ e regula tor . When the magneto output drops below th e specified pr eset r eg u Ia tor voltage level, the regu I ator drops ou t of the system, providing maximum available voltage to the l oad at decreased speeds.

In th e first half of the operating cycle when line 1 i s po s itive with r espect to line 2, C 1 will charg e through CR 1, C 1, R2 and CR2 until the voltage drop across C 1 reaches the level ne ces sary to cause Z 1 to conduct. At this point, Q1 will draw base current and then pass current through CR 1, the emitter col lector of Q 1 and into th e gate of SCR. SCR is "turned on" and shun ts the output of the magneto.

In the second half cycle the shunting mechanism of the regulator is not operative.

VOLT AGE REGULATOR -

043299

If th e re is a sufficiently h eavy load on th e magn e to during the first half cycle, the load e ffectively holds the voltage output to a value les s than that required to turn the SCR on and therefore full output goes to the load.

FIG. 3-12

3 6

SERVICE MANUAL 19 75 SCORPION WHIP

LINE 1 j

C l

LINE2 t.

L77777L77Z I Z7 1 7 / L // L I .~ ------------------------~----~

REGULATOR CONNECTOR

FIG: 3-13 MAGNETO VOLTAGE REGULATOR

(SOLID STATE)

PIN 043299

SCR

3 7


ELECTRICAL CONTROL

AND DISTRIBUTION

Functional Description

Power is supp li ed continuous ly to the tachometer m ec hanism and to the brake light switch, so that any time power is being generat e d, the tachometer will indicate and the brake li ght will go on if the brake is app lied .

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:

1. To the chassis at the rear end

2. To the chassis from wire harness at eng. connector.

3. To the stator plat e on the engine

HEADLIGHT HARNESS CONNECTOR

IGNITION SWITCH

CONN

VOLTAGE REGULATOR

CONNECTOR-~

MAIN ELEMENTS:

1. Main Wiring Harness

2. Seat Wiring Harness

3. Taillight Wiring

Harness

4. Safety Stop Switch

5. Break Light Switch

6. Hi lo Switch

7. Ignition Switch

HI-LO SWITCH

CONNECTOR

BRAKE LIGHT

SWITCH

CONNECTOR

SPEEDOMETER/TACHOMETER CONN. -~

SAFETY STOP SWITCH CONNECTOR '' -----.....,;.

SEAT HARNESS

' CONNECTOR f

ENGINE CONNECTOR

FIG. 3-14

(

SAFETY STOP

SWITCH/HARNESS ----~A'

3 8

BRAKE LIGHT

SWITCH/HARNESS

FIG. 3-15

~

~

<.

/ y _-.

(i j~\.~V _ (\ {_;

LLIGHTING

I

IG NITION

CO IL

-------,.r--y-.

~

/

/

LIGHT

SWITCH

•

I

E

VOLTAGE

REGULATOR

D

F I G. 3·16

I

SAFETY

STOP

I SWITCH

~

I •

•

.

-

,_.::_ -::::~~

TAILLIGHTS

BRAKE LIGHT n

· · - ·

TACHOMETER &

SPEEDOMETER

LIGHTS

WIRING SCHEMATIC (COLOR CODED)

ELECTRICAL DISTRIBUTION & CONTROL

1975 SUPER STINGER

:::1: m

)>

0

I"'"

C)

:t

-4

..0

......

U'l

"'

0

;:10

-a

0 z

:E

:::1:

-a

"'

;:10

< n m

3:

)> z c

,...


WIRING CODE (ELECTRICAL DISTRIBUTION & CONTROL)

Black

Blue

Brown

COLOR

Black/White

Green

Orange

Orange/Black

Red

Tan

White

Yellow

Yellow / Black

Yellow/Red

3 10

FUNCTION

Hot

Hot

Hot

FROM

Eng. Conne ctor

(Engine Ignition Coil)

Safety Switch Connector

Brake Switch

Hot

Hot

Hot

Hot (Hi)

Ground

Ground

Ground

Ground

Ground

Hot

Hot

Ground

Engine Conn ec tor (En g in e

Ignition Coil


Brake Switch Connector

Hi-Lo Switch (Hi)

Engine Connector

Engine Connector

Voltag e Regulat or

Connector

Instrument Connector

Taillight

Ignition Switch Connector

Engine Connector

Engine Connector

Hot

Hot

Hot

Hot (LO)

Hot

Hot

Hot

Voltag e R eg ulat o r

Connector


Brake Sw itch Connector

Hi-Lo Switch Connector

(Lo)



Hi-Lo Switch Con ne ctor

Ground

Hot

Engine Connector

Engine Conne c t or

TO


I gnition Switch




Brake Switch

Headlight Connector (Hi)

Chassis (Roll Bar Bracket)

Voltage Regulator

Connector

In s trument Connector

H ead light Connector

Chassis (Tunnel)

Electric Start (Regulator

Connector)

Instrument Connec t or

(Tachometer)

Instrum ent Connector

(Tachom e ter)


I gnition Switch Connec t or

Brake Lights

Head I ight Connecto r (L o)

Taillights

Hi-L o Switch Connec t o r

In strument Connector

(Lights- Tachometer,

Speedomete r)

Voltage Regulator

Connecto r

Voltage Regulator

Connector

)


SPECIAL TESTING - ELECTRICAL

Regulator Tests

1. Set point check (P /N 043299)

Use test circuit as shown below. Read voltage across regulator. Value should be approximately 13.8 volts.

120V lOOW OPEN

5 ..n...

----...N\1'-·

---·HI·-

• TEST

24V

REGULATOR SET POINT TEST CIRCUIT

3-ll

SERVICE MANUAL 197 5 SCORPION WHIP

TROUBLE SHOOTING (ELECTRICAL)

TROUBLE PROBABLE CAUSE REMEDY

No light s

Dim light s

Open Ci r cu it :

Faulty Switch(s)

Separated Co nnector( s )

Cut Wiring

Wiring s hort ed to gr ound:

Damaged In su lation

Faulty Regulator (Short ed SCR)

Shorted or open lighting coi l.

Faulty regulatorInc o rr ect r e gulator set point (t oo l ow).

Repair or rep l ace faulty or damag e d e l ement .

Repair or replace damaged or faulty e l ement.

Replace regulator .

Replace armature p lat e .

Rep l ace regulator.

Burned out lights (all)

Faulty regulator Incorrect Set

Point (too high) .

Replace regulator and failed bulbs.

Burned out lights (individ ua l)

Burned out light s

Engine won't run

Weak or no spark

Engine won't run-

Adequate spark.

Unacc e ptable

Engine Performance

Fa il ed bulb . Replace bu lb .

Intermittent short in wire harne ss . l. Open or s horted winding s in ignition co il s (stator).

2. Open or shorted windin gs. in external ignition co il.

3. Shorted condenser- dirty o r worn.

4 . Damaged (burn ed ) points . l. Burn e d or f ouled plug s.

Repair or r ep l ace wire harness. l. Rep l ace armature p lat e.

2. Replace externa l coil.

3. Replace condenser .

4. Replace points. l. Replace plugs. Determine that correct plugs are b ei ng u se d.

CHECK ENGINE TROUBLE

SHOOTING .

2. See Engine Trouble Shooting

Section

See Engine Tr ouble S hooting

Section

(

3-12

.

.

_

? •

(

1975

Scorpion

Whip

Service Manual

Clutch/Drive

Section

4-1


DRIVE SYSTEM


T h e main e l eme nt s included in thi s s ystem are:

1. Drive C lut ch

2. Drive Belt

3. Driven Clutch

4. Chain Case with s prockets, chain and chain tensioners.

5 . Driv e s haft with track drive sprockets.

The power from th e eng ine is transmitt e d through this system to the track in se quence of elements li s ted above to prop e l the machine.

Th e driv e clutch, belt and driv e n clutch serve as a torque converter. The torque co nv e rter on the sno wmobile "down shifts " to a lower ratio as the track load in creases as readily as it "up shifts" wh en the track l oad decreases.

To accomplish the automatic shifting, the movable sheave of the driven clutch is fitted with a helical ramp which is gu i ded by a follower. This sheave is controlled by a spring pre-stressed in tor sio n and compression to hold the sheaves together at the maximum p it c h diameter.

Und er acceleration, th e torque from th e engine i s greater than the demand from the track . The drive c lut c h then closes, for c ing the belt outward between the s heaves . Belt tension and wedging action i s unbalanced at the driven clutch and th e shea v e f aces are wedged open against the h e lical cam . This action w ind s up and compresses the spr ing.

Under s teady running, all forc es are balanced and the belt chooses a ratio at which this balance exists.

Under deceleration, the driven sheave i s s tall ed s lightly, whi c h unbalances the forces so that th e sheave is forced to a new larger pitch diam e t e r. B e lt tension is thus increased, the wedging action opens drive sheave and a new lower pitch diameter is c h ose n to again bring all forces to balance.

) j

4 · 2

DRIVE CLUTCH DISASSEMBLY

1 . Raise hood and clutch guard. (S ee Figure 4 -1 )


FIG 4-1

2. Remove clutch attaching bolt and bell retaining bolt. Use impact wrench capable of 75 or more ft. lb s. torqu e (In the field alternate method may be used.) Making sure ignition is off, run engine up on compression using %" socke t and ratchet. Strike ratchet with plastic or rubber mallet. (See Figure 4-2).

3. Remove bell housing (See Figure 4-3.)

FIG 4-2

FIG. 4-3

4 3


4 Movable sheave should slide off spline easi ly. Next remove spr ing and retainer.

(See Figure

4-4.)

5. Remove snap ring retainer and idler bearing if necessary. (See Figures 4 -5 and 4-6.) ~ /

FIG 4-4

FIG. 4-5

FIG. 4-6

4 4

(

6 . If necessary to remove stationary sheave, insert plug (2 13/16" long x 3/ 4" diameter) in stationary 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


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 retention of lubricant.

Inspect snap ring groove on stationary and spring retainer for wear.

Inspect bell housing for cracks, particularly in center area near spline.

4-6

FIG. 4-9

FIG. 4-10

)

FIG. 4·11

)

'

RE-ASSEMBLY OF DRIVE CLUTCH

CAUTION: If stationary has been removed, assure that there is no grease on either the shaft or sheave before reassembly.

SERVICE MANUAL · 1975 SCORPION WHIP r

Re-install idler bearing, snap ring, retainer and spring. Place weight arms on movable sheave (after checking them for lubrication).

Attach retainers, checking to see that the small locating hole in the bearing aligns with the detent on inner face of retainer. Install torque plug and torque plug retainer. Install 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 a.lignment. Install clutch attaching bolt. Torque on both bolts to 50 ft. lbs.

)

4-7


DRIVEN CLUTCH DISASSEMBLY

1. Remove brake cable at chain case end.

2. Remove chain tensioners, unbolt and remove top sprocket and chain .

DRIVEN SHAFT LOCKING BOLTS

CHAIN---------------~~~~~

CHAIN TENSIONER--------------t

FIG. 4-12

FIG. 4-12A

4-8

(

)

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.}

SERVICE MANUAL • 1975 SCORPION WHIP

CAM TOP

FIG.4-13

FIG. 4-14

FIG.4-15

4-9


4. Remove key and main spring. (See Figure 4-

16.)

KEY

-,

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. 4-16

(

)

FIG. 4-17

FIG.4-18

4-10

(

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


DRIVEN CLUTCH INSPECTION

In spe ct s nap ring groove for wear.

In spec t H e li c al ramps for wear and breakage.

( See Fig. 4-13)

In s p ec t bronze bushing in cam bottom for any s i g n s of looseness or s lippage _ (should be staked in so lidly).

R o tat e and c he c k bearings visually.

In s p e ct s h e ave s for cracks particularly around bo lt h o l es .

C h ec k s pline s and threads on sprocket side of m a in s haft for w e ar, crossthreading, etc.

RE ASSEMBLY OF DRIVEN CLUTCH

Atta c h s tationary sheave to clutch shaft. Assembl e c am bottom and movable, then place on shaft f o ll o w e d by the woodruff key and main spring .

Pla c e cam top on shaft , preloading spring lj 3 turn and install washer and snap ring.

Up o n replacing the driven clutch in chaincase, c he c k to a ss ure that the 0-ring in chaincase bore is intact and in good condition. Also check 0-ring in c haincase cover before installation. Connect brake cable. (See Fig. 4 12).

4 12

(

(

DRIVE BELT SPECIFICATIONS

Drive belt width 1 1 /8 - 1 3/16 inches

Drive belt outside diameter inches.

43 1/8 - 43 1/4

Clutch offset (Drive to Driven)- 3/8 inch

Center to center distance- 10 1/2 inches

(Drive clutch to Driven clutch)

I

SERVICE MANUAL • 197 5 SCORPION WHIP

( .

0

ALIGNMENT BAR

(FOR MEASURING 3/8" OF

DRIVEN CLUTCH--

FIG. 4-20

4 13


CHAIN CASE DISASSEMBLY

Remove brake cable at chain case end. Remove cover, tensioners, upper and lower bolts. Remove sprockets with chain. Remove bearing flange bolts and 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. Before tightening case to tunnel be sure to adjust case to achieve correct center distance of -

10 1/2" between center of driven and drive clutches.

Reverse procedure to install.

REMOVAL OF FRONT DRIVE SHAFT

Remove brake cable at chain case end. 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. (It is necessary to detach forward end of pararail 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

FIG. 4-21

4-14


)

COLLAR

BEARING

0-RING

Inspection of Drive Shaft

Observe shaft for signs of stress, cracks and bending, 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.

BEARING FLANGES-L-------'

4-15


TROUBLE SHOOTING

The operating diameter of the drive and driven clutch governs the ratio of reduction or advantage 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

Engine Overspeed: 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.

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).

REMEDY

Disassemble clutches examine and replace malfunctioning parts.

(

Replace belt. Correct center to center distance (see belt specs .

)

Replace incorrect sprocket.

Replace tach.

( )

Replace belt.

Excessive vibration of drive train:

Excessive noise from front drive system:

Track may be too loose allowing sprockets to slip over drive lugs or "ratchet".

Chain may be slipping over teeth on sprockets.

Malfunction of front drive bearings.

Cha1n case may be dry of oil.

Correct track tension.

Check and replace broken or weak chain tensioners.

Replace bearings.

Disassemble and check - chain, sprockets and chain case cover seal (0 ring) re place worn parts and reassembl e _ Refill with oil check level and check for leaks.

4 16

1975

Scorpion

Whip

Service Manual

Suspension

Section

5-l


FUNCTIONAL DESCRIPTION:

The four main elements of a snowmobi l e suspension are:

1. Skis

2. Track Suspension

3. Seat

4. Operator

All elements work together to perform the suspension functions to th e 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. In crease ground contact and improve trac tion.

On the 1975 Whip, 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 ab l e to tra verse marginal snow conditions without damaging effec t s to the suspension system.

NOTE: The suspension on the 1975 Whip may have ei ther two or three rear idler wheels, depending on time of manufacture. All pictures and diagrams show the three rear idler ! system.

Assembly and disassembly procedure for. the two idler sys t em i s the same as s hown for the three idler system with minor changes. l

5 -2

(

[

(

( c

SERVICE MAN UAL - 1975 SCORPIO N WHIP

FIG. 5-1 "PAR A-RAIL ®" G ROUP

5 3


SUSPENSION SYSTEM- REMOVAL, DISASSEMBLY, ASSEMBLY

For the removal, maintenance and installation of the "Para Rail

®

Snowmobile Suspension", we will refer to the "Para-Rail" group for identification of component parts by the numbers 1 through 57 .

(A) REMOVAL

1. Remove the two hex cap screws, #56 and wash ers , #57.

2 . Rai se and block rear of vehicle off the ground .

NOTE:

In Figs. 5-3 through 5 6 the track ha s been r e moved for clarity of illustration.

3 . Remov e the two nut s , #51, from the two eye bolts, #11.

FIG. 5-2

)

FIG. 5-3

I

5 · 4

I

)

4. Remove the two whiz lock screws, #20 securing the rear suspens ion plates to the rear axle.


FIG. 5-4

5 . Rel e ase the track tension by loosening the tw o sc r ews, #46.

(

6 . Remov e hex screws, #53 and nut, #54, on the two suspension plates. Remove plates.

FIG. 5-5

(

FIG. 5-6

5 · 5


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 r e moved from the track and tunnel.

(B) DISASSEMBLY"PARA-RAIL ® -SNOWMOBILE

SUSPENSION"

1. Bracket axle adjustm e nt #42

Remove the four lock nuts, #22.

(4) hex scr e ws, #21 and

FIG. 5-7

)

FIG. 5-8

5 6

2. Springs #2 #4

Place suspension on the floor and install spring release tool.

SE RVICE MANUAL - 1975 SCORPION WHIP

To release the springs from th e spools, #18, th e r ear of "Para Roil

®

Snowmobile

Suspension" must b e held down whil e downword pres su re i s applied with the right arm and upward pressure with the l e ft arm .

FIG. 5-9

3. Linkage Arm #30

Remove the two screws , #25, washers

#26 and #48.

Remove the two button head screws,

#33 and spring retainers, #32.

FIG. 5-10

0

~

FIG. 5-11

5 7


4 . Bogey Whe e l #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 rem oved from the remaining shafts, bogey whe e l s, and tube spacers. The "Para-

Rail

®

Snowmobile Suspension" is completely disassembled at this time.

.it. ~

I

FIG. 5-12

(

FIG. 5-13

FIG. 5-14

5 8

(C)

ASSEMBLY

1 . Prior to assembly procedure, ensu re that all components are clean and a ll defective parts hav e been replaced.

2. Apply a coat of low temp erature grease to all shafts prior to assembly. (Scorpion c lutch lub e 906800 may be used.)

3. Reverse procedure as outlined for disassembly.


NOTE: Ensure that all tub e spacers and bogey wheels are assembled in th ei r respective areas on the shafts.

( )

Torque requirements for assembly are:

ITEMS

20

21

22

25

53

54

1

TORQUE

50-60 Ft-Lbs.

5-19 Ft-Lbs

1 519 Ft Lbs

1 519 Ft Lbs

1 5 -1 9 Ft-Lbs

15-19 Ft-Lbs

(

'

5 9


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 bottoming 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 1/2" to 6".

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 th e nuts on the eye bolts securely when the 4 1/2" 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 Distributor as an accessory item.

5 l 0

( )

)

(


(

"PARA-RAIL

®

-S NOWMOBILE S U SPEN-

SION": TRACK TENS I ON

Proper track tension is ex tr eme ly im po rta nt to assure long l ife of all associated components and efficiency of the t rack drive syste m .

The track tension should be c h ecked at the fo ll owing interva l s: c

1 . When the machin e is new (dealer preparation).

2 . After the first 10 hours.

3 . Every 30 days, or 200 miles of opera ti o n .

4. At the star t of each sno w season .

The following procedu r e app l ies t o all "Para-

Rai l ® Snowmobi l e Suspensio n " equipped

Scorpion snowmobi l es:

1. The t rack s hould be at r oo m tem perature or should have been recently run to remove any stiffness, caused by co l d weather.

2. Elevate the rear of the machine.

3. Adjust each "Track Jack " to one and one quarter inc h ( 1 V4).

4. Insert both "Track Jacks" b e tw ee n th e track and both bogey wh ee ls, 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 vi sib le or aligned with the lip of the cylinder. Ad ju s tment i s required if the green ring i s 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 e i ther tighten or loosen the adjustment bolts until proper adjustment is measured on both "Track Jacks " (gr ee n ring aligned with lip on cylinder).

7. Retighten the lock nuts on th e track ad justment bolts , as well as the rear suspension mounting screws.

NOTE: Tra c k Jacks " are available at Scorpion, Inc. It is an accessory item, Part

#90 173&.

REAR SUSPENSION

MOUNTING SCREWS ------i"_,~.J'

TRACK ADJUSTMENT

BOLTS ----------~

FIG. 5-16

5 ll


IN THE EVENT "Track Jacks" are not avai l able, the following procedure may be employed to achieve

track tension:

l. The track should be at room temperature or should have been recently run to remove any stiffness, caused by cold weather.

2. Elevate the rear of the machine .

3. Apply ten ( l O) lbs. of force or weight evenly distr i buted across the track under both bogey wheels, l ocated 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 we l l as the rear suspension mounting screws (rear of tunne l just below seat), and either tighten or loosen the adjustment bolts to achieve the

1 1/4 inch clearance between track and bogey wheels.

5. Remove ten (l 0) lbs. force or weight and retighten the lock nuts on the track adjustment bolts, as well as the rear suspen sion mounting screws .

)

)

5 12