Evinrude & Johnson E-2035Q 1973 User manual

1973
EVI RUDE ~ ~ ~
-&JOHNSON
SNOWMOB ILE
PART NO. 406151

SECTION 1
INTRODUCTION
SA F E TY SYMBOLS
THE P URPOSE OF SAFETY SYMBOLS IS TO
ATTRACT YOUR ATTENTION TO POSSmLE
DANG ERS. THE SYMBOLS, AND THE EX-
PL ANA TIONS WITH THEM, DESERVE YOUR
CAR E FUL ATTENTION AND UNDERSTAND-
ING. SAFETY WARNINGS DO NOT, BYTHEM-
SE LVES, ELIMINATE ANY DANGER. THE IN-
STRUCTIONS OR WARNINGS THEY GIVE ARE
NOT SUBSTITUTES FOR PROPER ACCIDENT
PREVENTION MEASURES.
SYMBOL
~\ SAFETY
~WARNING
o PROHIBITED
ONOTE
MEANING
FAILURE TO OBEY A
SAFETY WARNING MAY
RESULT IN INJURY TO
YOU OR TO OTHERS.
WARNS YOU AGAINST AN
ACTIVITY WHICH IS, OR
MAY BE, ILLEGAL IN
YOUR AREA.
ADVISES YOU OF INFOR-
MATION OF INSTRUC-
TIONS VIT AL TO THE
OPERATION OR MAINTE-
NANCE OR YOUR EQUIP-
MENT.
Before proceeding with any repaixr adjust-
ments on this snowmobile, see SAFETY
WARNINGS on inside front cover and on pages:
5- 6 6-6 7-3 7-18 7-19 8-2 9-5 10-2 10-3
, , , , , , , , ,
11_4 and 12-5.
INTRODUCTION
SPECI FI CATIONS
GEN ERAL SNOWMOBI LE IN FO RMATION
TROUBLE SHOOTING
TUNE-UP PROCEDURES
FUEL SYSTEM
IGNITION AND
ELECTRICAL SYSTEM
MANUAL STARTER
ENGINE
11
1-1
I
L- __ D_ R_IV _E_T_ R_A_IN ____ ____ _________ ~
STEERING , TRACK AND SUSPENSION
LUBRICATION AND STORAGE

1- 2
The snow vehicle has been designed and built for dependable, high
performance. It is important to every snow vehicle owner to be able
to receive skilled and thorough service for his vehicle when necessary.
It is important to the service dealer to be able to offer the type of skilled
service which will maintain the customer's satisfaction.
This manual, together with the regularly issued service bulletins and
Parts Catalogs, provide the serviceman with all the literature necessary
to service the model in question. An effort has been made to produce a
manual that will not only serve as a ready reference book for the ex -
perienced serviceman, but will also provide more basic information for
the guidance of the less experienced man.
The Parts Catalogs contain complete listings of the parts required
for replacement. In addition, the exploded views illustrate the correct
sequence of all parts. This catalog can be of considerable help as a
reference during disassembly and reassembly.
The Section Index on page 1- 1 enables the reader to locate quickly any
desired section. At the beginning of each Section is a Table of Contents
which gives the page number on which each topic begins. This arrange-
ment simplifies locating the desired information within this manual.
Section 2 lists complete specifications on the snowmobile. All general
information, including 2 cycle engine theory, trouble shooting, and tune
up procedures, are given in Sections 3 through 5 of this manual.
37323
Figure 1-1
)
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Sections 6 through 11 provide fully illustrated, detailed, step-by-step
disassembly and reassembly instructions and adjustment procedures.
Section 12 provides lubrication and storage information. In this way,
the texts treat each topic separately; theory and practice are not
intermixed. This makes it unnecessary for the experienced service-
man to reread discussions of theory along with specific service in-
formation. Illustrations placed in the margins provide unimpeded
reading of explanatory text, and permit close relationship between
illustration and text.
Read this manual carefully to become thoroughly familiar with the
procedures described, then keep it readily available in the service shop
for use as a reference. If properly used, it will enable the serviceman
to give better service to the snowmobile owner, and thereby build and
maintain a reputation for reliable service.
This service manual covers all phases of servicing the snowmobile,
however, new service situations sometimes arise. If a service question
does not appear to be answered in this manual, you are invited to write
to the Service Department for additional help. Always be sure to give
complete information, including model number and vehicle identifica-
tion number.
All information, illustrations, and specifications contained in this
literature are based on the product information available at the time of
publication. The right is reserved to make changes at any time without
notice.
1. Hand Brake and Parking
Lock
2. Hi-Lo Beam Headlight
Switch
3. Tachometer
4. Ignition / Lights Switch
5.
Speedometer
6. Safety Stop Switch
7.
Throttle
8. Compression Release
9. Primer
10. Manual Starter Handle
11.
Instrument Panel Door
12. Hood Latches
13. Reverse Control
14. Neutral Lockout
15. Choke
Figure 1-2
1-3

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2- 1
SECTION 2
SPECIFICATIONS
TABLE OF CONTENTS
SPECIFICATIONS. • • • . • . . . . . . . • • • • . 2-2
TORQUE SPECIFICATIONS ...•.••...• 2-3
Snowmobile Special Service Tools - Quiet Models
PART NO.
378103
404032
*
426020
383966
*
375632
114146
113971
162282
261906
261132
261131
261129
317829
317830
604659
DESCRIPTION
Flywheel Puller
Wrench - Primary Drive
Truarc Pliers
Ring Compressor
Spring Winder
Heli-Coil Installers & Inserts
Spark Plug Wrench
Splined Wrench
Flywheel Holding Tool
Drive Alignment Gauge
Disassembly Tool (Primary Drive)
Retaining Ring - Bearing Puller
Half steel - ' Bearing Puller
Extractor - Crankshaft Bearing
Driver
Cone
Air Gap Gauge
*Refer to the Tool Catalogue

2-2
SPECIFICATION S
oPROHIBITED: Snow Vehicles are not manufactured for highway
use and the manufacturer does not represent that they are equipped with
all the devices legally required for such use.
Length
Width
Height ....
· . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 107 inches
• . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 37 inches
· . . . . . . . . . . . . . . . . . . .. 44.9 inches with windshield
37 inches without windshield
Engine .•.•....•...........•••••• OMC 2- cycle opposed twin
Rating ......•••..••.•.••••.•••• Maximum 30 hp at 5800 rpm
Starter ••.......•................... Electric and manual
Variable speed drive ....• Centrifugal operated sheave engages V-belt
Overall ratio ••••.•••••.•....•••••••...•..••• 5.07 to 1
Final drive ...•.•...•.••....•......... ABA 35 double chain
Sprocket ratio • . . . . . . . . . . • • . • . . . . • • • • • • . • . . .. 16 to 42
Reverse transmission ..•.•.......... Dog clutch and bevel gears
Mufflers ............•.•... Tuned mufflers for quiet operation
Brake .•..........••...•••.•..•.• Disc type, hand operated
Throttle. • . . • . • . . . • . . . . . . . . . • . . . . . • . . • . . Thumb operated
Track ..•.••..•. Polyurethane - Specially designed-fully adjustable
Width ...•..•..•.•.....•••......••....•. 20.5 inches
Skis ........... Formed steel, equipped with shock-absorbing leaf
springs and replaceable wear runners
Seating capacity ..........•..... Two adults. Vinyl coated cover,
molded urethane foam cushion
Hood ..................... Molded fiberglass
Head lamp .......................... Sealed beam GE 4002
Tail lamp / stop lamp ............................ GE 1157
Fuel tank. . . . . . . . .. Capacity 4.3 Imperial gallons, 5.5 U.S. gallons
Lubrication ...................... OMC brand 50:1 lubricant
Carburetor Needle Adjustment (Bendix Float Type Carburetor)
High speed ........ 1-1 / 4 turns off seat minimum
Low speed . .. 1 to 1-1 / 4 turns off seat
RPM Ratings
Idle ..... . . . . . . . . . . . . 1000 -1200
Transmission belt engaging speed. . . . . . . . . .. Approx. 2500-2800
Maximum RPM at which neutral control will operate ... Approx. 2000
Ignition
Breakerless magneto C.D. (Capacitor Discharge) ignition
Spark plug .....•..•..•.•••••••••..•.•.• Champion UJ2J
Spark plug gap . . • . . . . . . . • . • • • • • . . . • . • .. .028 -.033 inch
Advance sensor coil resistance ................•. 14-16 ohms
Retard sensor coil resistance ............ 27-29 ohms
Magneto charge coil resistance (2 coils) total of .... 875 ± 75 ohms
Ignition coil secondary resistance ............. 1900 ± 190 ohms
Lighting coil resistance ..........•.... 1.3 ohms total both sides
Battery •. 12 volt Prestolite Type 2920 or equivalent with a minimum
32 ampere hour rating, and with a minimum of 2.2 minutes
Engine
cold starting capacity at 150 amperes diSCharge, 0° Fahren-
heit, and a 5-second voltage reading of 7.8 volts. Dimensions
in inches are approximately 7-3/4 long, 5-1/8 wide and 7-1/4
high (to top of terminals). Weight dry 17 lbs., wet 21.4 lbs.
Electrolyte to fill 0.44 U.S. gallons. Specific gravity 1.265
Bore and stroke • . . • • . . . • . . . . . . . . . . .. 2-3/4 x 2-1/4 inches
Piston displacement . . . • . • . • • • . • • •. 26.7 cubic inches (437 cc)
Compression ratio ........•......•••••. . . • • • •• 6.8· to 1
Cylinder compression • . . • . . . . . . . . . . . . . . • . Minimum 105 PSI
Ring diameter ......•.•.•..••••.•.•.•..... 2- 3/4 inches
Ring thickness . . . • • • • . • • . . . . . . • • • • • • • . . . • . •. 1/16 inch
Clearances
Piston - wrist pin. . • . • • • • • . • • • • • • • • • • • • • . • . .• Press fit
Piston ring gap .•••..••••.......•.•••••••••. .007-.017
Piston ring - ring groove. • • • • . • • • • . . . • . • . . . • • .. .002-.004
Cylinder - piston .•••••.••.• Top of piston to cylinder .012 -.015
Bottom of piston to cylinder .006 -.008
SpeCifications and features may be changed at any time without notice
and without obligation towards vehicles previously manufactured.

TORQUE SPECIFICATIONS
PART
APPLICATION
SIZE TORQUE
IN. / FT. /
LBS. LBS.
*Nut
Ball Joint to Steering Arm &
Rod Ends to Steering Column
3/ 8-24 18 - 20
Nut Cable to Solenoid 36- 60
*Screw
Connecting Rod
29 - 31
*Screw
Crankcase
60 - 80
5-7
*Nut cYlinder to Crankcase
18 -20
*Screw
Engine to Engine Frame
Assembly
3/ 8- 16
33 -38
*Nut Exhaust Manifold to Cylinder
5/ 16 - 24 10 - 12
*Screw Flangettes to Frame
3/ 8-16 20-25
*Nut
Flywheel
40-45
*Screw Engine Frame to Main
Frame
3/ 8-16
18 - 20
* Nut Front and Rear Truck Axles
5/ 8- 18 35- 45
*Screw Idler Axle to Frame
3/ 8- 16
20 - 25
Setscrew Locking Collar #10- 32
25 - 35
Bolt and
Rear Axle Pivot
Nut
5/ 16 - 24 12 - 15
Setscrew
Rear Sprocket
3/ 8-16
18 -20
Nut Rear Suspension to Frame
5/ 16 -
24
1 90-100 I
12 - 15
*Nut
Runner to Ski 5/ 16- 18
* Nut
U Bolt to Saddle
10- 12
*
Spark Plug
20 - 25
* Nut
Throttle Cable Adjusting
Screw
5/ 16-18 60 - 80
*Screw Truck to Frame
3/ 8-16 25 - 30
*Screw
Truck to Frame
7/ 16-14
25 - 30
*Screw
Secondary End Cap to
Shaft
3/ 8-16 2 2- 25
Screw Drive Sprocket
1/ 4-20
15 - 17
*Screw Shifter Clevis to Pinion
Shaft
1/ 4- 28
160-180
* Screw Primary Sliding Sheave
to Hub 1/ 4-20 7-10
*Bolt
Primary End Cap to Main
Shaft
3/ 4- 16
I
90 -100
Screw #6 7-10
Screw
#8
15 - 22
Screw
General
# 10
25 - 35 2-3
Screw
7
Torque
#12
35 -40 3-4
Screw
ReqUirements
1/ 4 60-80 5-7
Screw
5/ 16 120-140
10 - 12
Screw
3/ 8 220-240
18 - 20
Specifications and features may be changed at any time without notice
and without obligation towards vehicles previously manufactured.
*Use Torque Wrench
2-3

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3-1
SECTION 3
GENERAL SNOWMOBILE INFORMATION
TABLE OF CONTENTS
TWO-CYCLE ENGINE OPERATION . . • • • •. 3-2
COMPRESSION. . . . . . . . . • • • • • • • • • • •• 3-2
CARBURETION • • . . • • . . . • • • • . . • . • • • • 3-3
IGNITION. . • . . • . . . . • • • . • • • • . . • • . .• 3-4
LIGHTING SYSTEM • . . . . . • . • • . • . • . • •. 3-4
POWER FLOW. • • • • • • • • • • • • • • . • . • •. 3-5
PRIMARY DRIVE. . . • • • • • • • . • • . • • • • 3-5
NEUTRAL CONTROL. • . . . . • • • . • • • •. 3-6
SECONDARY DRIVE. . . . • . • • • . • • . • .. 3-6
REVERSE TRANSMISSION. . • . . . . . • • •. 3-6
II

3-2
POWER STROKE - DOWN
COMBUSTION OF
FUEL-AIR
ROD
COUNTER-
BALANCE
AXIS OF
ROTATION
Figure 3-1
17133
FUEL INTAKE AND EXHAUST
LEAF VALVES
EXHAUST
PORT OPEN
Figure 3-2
17 134
COMPRESSION STROKE - UP
EXHAUST
PORT CLOSED
Figure 3-3
17135
TWO CYCLE ENGINE THEORY
An internal combustion engine is one in which fuel is burned inside the
engine: a charge of fuel is introduced into a combustion chamber
(cylinder) within the engine and ignited. The energy released by the
expansion of the burning fuel is converted to torque by the piston, con-
necting rod, and crankshaft.
Internal combustion engines are classified as either four-cycle or
two-cycle engines . The "four" and the "two" refers to the number of
piston strokes required to complete a power cycle of intake, compres-
sion, power, and exhaust. A piston stroke is piston travel in one direc-
tion only; up is one stroke, down is another. In a four-cycle engine,
two crankshaft revolutions, or four strokes, are required for each power
cycle. In a two-cycle engine only one crankshaft revolution is required
per power cycle.
In a two-cycle engine, the ignition of the fuel-air mixture occurs as
the piston reaches the top of each stroke. The expansion of gases drives
the piston downward (see Figure 3-1). Toward the end of the downward
stroke, ports which lead from the cylinder to the exhaust system are
uncovered. The expanding exhaust gases flow into these ports, reducing
pressure in the cylinder. Immediately after, intake ports are opened.
These ports connect the cylinder with the crankcase where a mixture
of fuel and air has been developed by carburetion. The downward motion
of the piston compresses this mixture and forces it through the intake
ports into the cylinder. See Figure 3-2.
The inrushing charge of the fuel-air mixture helps to eject (scavenge)
the last of the exhaust gases from the cylinder. At this point, the mo-
mentum of the flywheel is required to return the piston to the top of the
cylinder. As the piston begins its up-stroke, it closes the intake and
exhaust ports and begins to compress the fuel-air mixture trapped in the
cylinder. See Figure 3-3. The upward motion of the piston also re-
duces the pressure in the crankcase. The resulting crankcase suction
opens leaf valves which admit a fresh charge of air and fuel from the
carburetor into the crankcase, thus preparing for the next power cycle.
Near the top of the piston stroke, the compressed fuel-air mixture is
ignited, the piston is driven downward, and the power cycle is repeated.
At full throttle, this cycle may be repeated more than five thousand
times every minute.
COMPRESSION
The pistons and piston rings perform two functions. They compress
the mixture of fuel and air in the cylinders before ignition, and receive
the force of the power after ignition. For maximum compression, the
cylinder must be round and the piston and piston rings correctly fitted
to it. The rings must be properly seated in the ring grooves and free
to expand against the walls of the cylinder. The rings will not retain
the force of combustion if the pistons and cylinder walls are excessively
worn, scored, or otherwise damaged, or if the rings become stuck in
grooves because of carbon accumulation. Escape of compression past
the piston rings is referred to as "blow-by" and is indicated by dis-
coloration or carbon formation on the piston skirt.
Cylinder bores normally wear with operation of the engine. The de-
gree of wear will vary with length of operation, efficiency of lubrication,
and general condition of the engine. Excessive cylinder wear results
in loose fitting, pistons and rings, causing blow-by, loss of comprgggion,
loss of power and inefficient performance.

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Piston rings are formed in such a manner that when installed on the
piston, they bear against the cylinder wall with a light, even pressure.
Excessive ring pressure against cylinder wall increases friction, caus-
ing high operating temperature, sluggish performance, and abnormal
wear or scoring. Insufficient pressure allows blow-by, which reduces
power, and causes overheating and carbon formation· on piston skirt.
Compression leakage may also occur at spark plugs. A cracked spark
plug insulator will cause similar trouble. Although compression is pri-
marily dependent on the piston, rings, and cylinder, these other sources
of leakage should be investigated when compression loss is noted.
Since the ring tends to flex as it fOllows the cylinder contour during
engine operation, clearance or gap must be provided between the ring
ends to prevent butting. The ring gap also allows the ring to expand
(elongate) as engine temperature rises during operation. Insufficient
gap clearance will cause the ring to bend or warp as it flexes and ex-
pands; excessive gap clearance will permit loss of compression.
Compression leakage will occur if the compression relief valve link-
age is adjusted with insufficient clearance on the cable ends. The relief
valves vent combustion chamber pressure through a by-pass port.
Compression may also be affected by the fuel induction and exhaust
systems. Since the fuel vapor is first compressed in the crankcase,
leakage here will affect engine performance. Possible trouble spots
include leaf valve assemblies, seals between crankcase halves, and
crankshaft bearing seals . Exhaust ports which have become clogged
because of excessive deposits of carbon will hinder the efficient transfer
of exhaust gases.
Excessive carbon build-up on piston heads or elsewhere in the cylin-
der walls can result in a loss of power.
Following the trouble shooting procedures in Section 4 and the recom-
mended tune-up procedures given in Section 5 will assure that all areas
affecting fuel induction, compression, and exhaust will be considered as
part of every trouble shooting procedure. An engine with low or uneven
compression cannot be successfully tuned for peak performance. It is
essential that improper compression be corrected before proceeding
with an engine tune-up.
CARBURETION
Gasoline, in its liquid state, burns relatively slow with an even flame.
However, when gaSOline is combined with air to form a vapor, the mix-
ture becomes highly flammable and burns very fast. To obtain best re-
sults, the fuel and air must be correctly proportioned and thoroughly
mixed. Fuel is atomized by spraying thru a nozzle into an air stream.
This is the function of the carburetor.
The atomized mixture is later vaporized in the carburetor barrel,
intake manifo~d and crankcase.
GaSOline vapor will burn when mixed with air in a proportion from
12:1 to 18:1 by weight. Mixtures of different proportions are required
for different purposes. Idling requires a relatively rich mixture; a
leaner mixture is desirable for maximum economy under normal load
conditions; avoid lean mixtures for high speed operation. The carbure-
tor is designed to deliver the correct proportion of fuel and air to the
engine for these various conditions.
3-3
INDUCED LOW / VENTURI
PRESSURE ~
~
FUEL FORCED UPWARDS
BY ATMOSPHERIC PRESSURE
Figure 3-4
HOLE FOR FUEL
PUMP PULSE
LEAVES
17 1 36
INTAKE
MANIFOLD
LEAF PLATE AND BASE ASSEM.
17 0 88
Figure 3-5

3-4
GROUND
ELECTRODE
CENTER
Figure 3-6
REFERENCE PICTURE
P - PERMANENT MAGNET
N - NORTH POLE SHOE
S - SOUTH POLE SHOE
F - FLYWHEEL
1713 8
C - LAMINATED COIL CORE
17137
Figure 3-7
The carburetor is essentially a simple metering device. Needle
valves permit a precise amount of fuel to flow to the carburetor throat.
A small chamber holds the fuel before it is consumed by the engine.
Nozzles in the carburetor throat extend down into the fuel chamber. The
upstroke of the piston creates a suction which draws air through the
leaf valves and the carburetor throat. At a particular point the throat
is restricted by a venturi (see Figure 3-4). The venturi has the effect
of reducing the pressure in the air stream, creating a partial vacuum
which draws fuel from the nozzle. As the atomized mixture is rushed
along to the firing chamber, it is swirled about in the air stream and
vaporized.
A throttle or butterfly valve in the throat regulates the amount of air
drawn through the carburetor. To vary the speed of the engine, the
throttle opens or closes, regulating the amount of fuel-air mixture
drawn into the engine.
A
richer fuel mixture is required for starting a cold engine. A sec-
ond shutter, called a choke, is placed into the throat to restrict the
flow of air. When the choke valve is closed, more gasoline and less
air is allowed into the air stream resulting in a richer fuel-air mixture.
When normal operating temperature is reached, the choke is opened
and the standard ratio of gasOline and air allowed to flow from the
carburetor.
The system which controls the intake of the fuel-air mixture in the
two cycle engine consists of a set of leaf valves which serve the same
purpose as the intake valves on a four cycle engine. The leaf valves are
thin, flexible metal strips mounted between the carburetor intake mani-
fold and crankcase.
When the piston is on the up-stroke, it creates a partial vacuum in the
crankcase. Atmospheric pressure forces the leaf valves away from the
body (see Figure 3-5), opening the passage between the carburetor and
crankcase. When the piston is on the down-stroke, it compresses the
crankcase Charge, forCing the leaf valves against the passage opening,
and sealing off the crankcase from the carburetor. Since the opening
and
closing may occur in excess of five thousand times per minute, the
leaves must be thin and flexible.
IGNITION
The capacitor discharge (C.D.) ignition system generates a high volt-
age electriC current which jumps the spark plug gap within the cylinder
and ignites the compressed fuel-air mixture in the cylinder. See Figure
3-6.
The (C.D.) ignition system is made up of the following major com-
ponents:
1. Flywheel assembly
4. Sensor plate assembly
2. Sensor rotor
5. Power Pack assembly
3. Stator and charge coil assembly 6. Ignition coils
7. Spark plugs
The following sequence of events will illustrate how this system works.
The flywheel rotates around the stator and charge coil assembly.
(See Figure 3-7.) The magnets in the flywheel and the (2) charge coils
generate a voltage. This voltage (AC) flows into the Power Pack.
Here it is changed to DC and stored in a capacitor. At the same time
the sensor rotor rotates by the sensor coils and a smaller AC voltage
is generated. This smaller voltage flows into the Power Pack and
causes an electronic switch in the Power Pack to turn on allowing the
voltage stored in the capaCitor to discharge into the primary of the
ignition coils.

c
One thing to note in this system is that there are two sensor coils.
Below the idle RPM range and up to approximately 900 RPM. the retard
sensor turns on the electronic switch in the Power Pack. At RPMs
over 900 the advance sensor coil generates enough voltage to turn on the
electronic switch in the Power Pack before the retard sensor does.
So, we have an automatic electronic advance built into the system.
An added feature of this snowmobile is the idle speed switch on the
carburetor. Closing the throttle closes the idle speed switch which
shorts out the advance sensor. This will cause the engine ignition
system to immediately fire in the retard position.
The ignition coil primaries receive the capacitor discharge vO,ltage
from the Power Pack, and induces a secondary voltage high enough to
fire across the spark plug gaps.
LIGHTING SYSTEM
The alternator coils produce alternating current which changes in
frequency and voltage in proportion to the engine speed.
This alternating current output is converted to direct current by a
diode bridge rectifier and used to charge the battery. Direct current
from the battery is then used to power the headlamp and taillamp, and
the electric starter motor.
The alternator output is automatically increased to maximum charge
when lights are turned on.
3-5
A. Neutral Lockout Plunger
B. Emergency Starting
Sheave
C.
Garter (Activating)
Spring
D. End Cap
E. Movable Half of
Sheave
F. Transmission Belt
G. Fixed Half of Sheave
H. Crankshaft
I. Ball Bearing
J. Spring Cup
K.
Compression Spring
L. Neutral Lockout Balls
M. Splined Shaft
N. Bolt, End Cap to Splined
Shaft
O. Spring
P. Neutral Lockout Rod
R. Spring
TRANSMISSION LOCKED IN NEUTRAL
17171
TRANSMISSION HIGH SPEED
POSITION - BELT ENGAGED
17172
Figure 3-8
Figure 3-9

3-6
POWER FLOW
The transmission assembly transmits power from the engine to the
front axle which propels the vehicle along the track. The primary
sheave assembly is attached directly to the crankshaft. The secondary
sheave assembly has its own mounting pedestal and is larger in diam-
eter than the primary sheave assembly. The two are connected by a
transmission belt.
PRIMARY DRIVE
The primary sheave is centrifugally operated and engages the trans-
mission belt when the engine speed reaches 2500 to 2800 rpm. When
the engine is rotating at idle speed or below 2500 to 2800 rpm, the trans-
mission belt rides on a ball bearing between the halves of the primary
sheave assembly (see Figure 3-8). The primary sheave assembly
halves are separated by a compression spring in the hub of the movable
sheave half.
As
the engine speed increases, centrifugal effect forces a garter
spring in the end cap outward against the contour of the end cap and
axially against the movable sheave half. As the sheaves are brought
together, the transmission belt is forced outward to ride on a larger
diameter of the primary sheave assembly, increasing belt speed (see
Figure 3-9). Since the belt length remains constant, the secondary
sheave halves spread , apart, allowing the belt to ride on a smaller diam-
eter. In this way, the engine transmits power through a variable ratio,
presenting the engine with a mechanical advantage most favorable for
the speed at which it is operating.
NEUTRAL CONTROL
A neutral control mechanism is used to prevent the drive from engag-
ing during starting, warm-up period, and idle. When the neutral lockout
plunger is actuated, a cone on the end of the plunger raises two balls
through the splines of the primary sheave assembly and into the path of
the movable sheave half, preventing it from engaging the belt. The
neutral control is spring actuated and will engage only when the engine
is below approximately 2000 rpm.
TIONING BECAUSE RPM TOO HIGH
17275
Figure 3-10

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When the engine is running above approximately 2000 rpm, the garter
spring will expand by centrifugal effect. See Figure 3-10. The garter
spring will then ride up the ramp of the end cap and push the movable
sheave toward the fixed sheave. In doing this, the movable sheave has
covered the holes in the splined shaft. When the neutral lockout rod
(P-Figure 3-8) is now pushed in, the spring loaded plunger (A-Figure
3-8) cannot move in because the moveable sheave now covers the neutral
lockout balls. Spring (R-Figure 3-8) will therefore be compressed as
shown in Figure 3-10. If the engine speed is now reduced to below 2,000
rpm, the garter spring will close and allow the movable half of the sheave
to move away from the fixed sheave. Spring (R) will then push the plunger
inward. The neutral lockout balls will then move outward, through the
splined shaft. The movable sheave will now be locked in the neutral
pOSition. See Figure 3-8.
SECONDARY DRIVE
The secondary drive mechanism incorporates a torque sensing device
that detects the need for more power for steep inclindes or deep snow.
The mechanism immediately forces the secondary sheaves closer to-
gether to raise the transmission ratio and provide a higher torque to the
drive chain and track.
The drive ratio varies from 3.3 to 1 in low to .67 to 1 in high which
yields an overall drive range of approximately 5 to 1. Power is trans-
mitted from the secondary sheave assembly through a drive chain to the
front axle.
The ratio between the secondary sheave assembly and the front axle is
16:42.
REVERSE TRANSMISSION
The reverse gear is designed as part of the secondary drive. In
"Forward" gear, the input shaft drives the output shaft directly by
means of a "dog" type clutch. IN "reverse" gear, the dog clutch is
released while a gear set engages to reverse rotation of output shaft.
o NOTE
Shifting
must be done with the engine at idle and machine at rest.
COOLING
Cooling air is drawn thru louvers on the right side of the instrument
panel. It is then passed thru openings under the manual starter and
pushed over the engine and thru the COOling fins. The warmed air is
discharged thru louvers on the left side of the instrument panel. See
Figure 3-11.
Figure 3-11
3-7

)

(
4-1
SECTION 4
TROUBLE SHOOTING
TABLE OF CONTENTS
DESCRIPTION. • • • • . . • • . . • . • . • • . . . .. 4- 2
TROUBLE SHOOTING PROCEDURES. • • • •• 4-3
STARTING. . • . . . . . . . • • • • • . . • • • •• 4-3
STARTING -MANUAL STARTER. • . • • .• 4-4
STARTING - ELECTRIC STARTER. . • . •. 4-4
RUNNING -LOW SPEED ONLY . . . • . • •• 4-4
RUNNING -HIGH SPEED ONLY. • . . • . •. 4-4
RUNNING -HIGH AND LOW SPEED. • . •. 4-5

4-2
DESCRIPTION
This section provides trouble shooting procedures for the snow ma -
chine. Steps to be followed in determining causes of unsatisfactory per-
formance are outlined.
Being able to locate the cause of trouble in an improperly operating
snow machine is as important as being able to correct the trouble. A
systematic approach to trouble shooting is important if the trouble is to
be located and identified in minimum time.
Any service operation can be broken down into three steps:
1. Identifying the problem
2. Determining the cause of the problem, and
3. Correcting the problem .
Familiarity with the factors which affect two-cycle engine perform-
ance is important in making a correct service diagno s is . Factors
which affect engine performance include the quality of the fuel and fuel
mixtures, compression, ignition, and proper drive system adjustment.
Engine theory, compression, carburetion, ignition and power flow are
discussed in Section 3. Correct fuel mixture for this snowmobile is
outlined on the inside front cover, and fuel blending is discussed in Sec-
tion 12. Familiarity with factors which contribute to abnormal per -
formance of an engine are similarly helpful. The skilled mechanic's
experience is a great asset here.
J

r
TROUBLE SHOOTING
PROCEDURES
Trouble Shooting to determine the caus~ of any
operating problem may be broken down into the fol-
lowing steps:
a. Obtaining an accurate description of the trouble.
b. Preliminary inspection.
c. Use of Trouble Check Chart to analyze engine
performance.
An accurate description of the trouble is essential
for trouble shooting. The owner's comments may
provide valuable information which will serve as a
clue to the cause of the problem.
A preliminary inspection should include the follow-
ing checks.
a. Correct spark plugs
b. Throttle linkage properly adjusted
c. Tank filled with fresh, clean fuel of the proper
mixture
d. Spark at each spark plug
e.
Carburetor adjusted correctly
f. Compression. Turn flywheel by hand or with
recoil starter. If compression is present, it
can be felt when turning through one complete
revolution of the flywheel. If little or no com-
pression exists in both cylinders, engine will
spin very easily.
STARTING
1. Hard to start or won't start
a. Empty gas tank
b. Incorrect gas-lubricant ratio
c. Old fuel, or water or dirt in fuel system
d. Fuel line improperly connected
e. Fuel line kinked or severely pinched
f. Engine not primed
g. Clogged fuel line or fuel filter
h. Clogged check valve
i. Carburetor adjustments too lean
j. Low speed needle bent or bowed
k. Engine flooded
4-3
1. Leaf valves not functioning properly
mo Faulty gaskets
n. Spark plugs fouled, improperly gapped, dirty
or broken
o. Loose or broken wire or frayed insulation in
ignition system wiring
p. Sheared sensor hub key
q. Faulty coils
r. Key switch, connector or grounded switch
wire
s. Binding in engine
t. Faulty sensor, charge COils, Power Pack
or connecting wiring.
2. Engine won't turn over
a. Cylinder wall corrosion, seized piston or
bearing
b. Engine improperly assembled after repair
3. Cranks over extremely easily
a. Spark plug(s) loose
b. Cylinder or pistons scored
c. Rings worn or carboned
d. Faulty crankcase gasket or crankseal(s)
e. Broken or damaged leaf valves
4. Won't start, but kicks back and backfires
a. Leaf valves broken or not seating
b. Sensor leads on Power Pack terminals #6 & #8
reversed
c. Timing out of adjustment (check sensor hub
key)
d. Advance
sensor faulty or out of adjustment
e. Power Pack faulty
5. No spark one cylinder
a. Faulty ignition coil, wire, or connections
b. Faulty Power Pack