High-Altitude Clutch Tuning; Chaincase Sprocket Adjustment; Suspension Adjustments - Yamaha MM700A Manual

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HIGH-ALTITUDE CLUTCH TUNING

When the snowmobile is operated at an altitude of more
than 3500 (1000 m), it may be necessary to adjust the
clutch to compensate for engine power loss. If the clutch
is not adjusted, the engine may bog down when the belt
engages. The engine may also bog when running in deep
snow. Both conditions can lead to premature drive belt
failure. Refer to Tables 11-13.
Refer to Chapter Ten for complete clutch service proee-

CHAINCASE SPROCKET ADJUSTMENT

Depending upon altitude, snow and track conditions,
different sprockets in the chaincase may be required.
Snow conditions that offer few rough sections may re-
quire less reduction. Less optimum snow conditions or
more rugged terrain require more reduction. Refer to the
recommended sprockets in Table 14. Replacement
sprockets and chains can be purchased through Yamaha
dealerships. Refer to Chapter Twelve for sprocket and
chain replacement procedures.

SUSPENSION ADJUSTMENTS

The suspension can be adjusted to accommodate rider
weight and snow conditions.
Correct suspension adjustment is arrived at largely
mental points that must he understood and applied before
the suspension can be successfully adjusted.
Ski pressure-the load on the skis relative to the load on
the track-is the primary factor controlling handling per-
formance. If the ski pressure is too light, the front of the
machine tends to float and steering control becomes
vague, with the machine tending to drive straight ahead
rather than turn, and wander when running straight at
steady throttle.
On the other hand, if ski pressure is too heavy, the ma-
chine tends to plow during cornering and the skis dig in
during straight line running rather than staying on top of
the snow.
Ski pressure for one snow condition is not necessarily
good for another condition. For instance, if the surface is
very hard and offers little steering traction, added ski pres-
sure is desirable. Also, the hard surface supports the skis
and does not allow them to penetrate when the machine is
running in a straight line under power.
On the other hand, if the surface is soft and tacky,
lighter ski pressure is desirable to prevent the skis from
sinking into the snow. Also, the increased traction af-
forded by the snow allows the skis to
pressure.
It is apparent, then, that good suspension adjustment in-
volves a thorough analysis relating to ski pressure versus
conditions. The suspension has been set by the manufac-
turer to work in most conditions encountered by general
riding. However, when the snowmobile is operated in
varying or more difficult conditions, adjust the suspen-
sion. It is important to remember that suspension tuning is
a compromise. An adjustment that works well in one situ-
ation may not work as well in another.
The rear suspension is equipped with a front suspension
arm and a rear suspension arm. Each arm is provided with
a shock absorber and a spring.
Refer to the following for adjusting the springs at each
location.
Front Suspension Spring Preload
The front suspension shock absorber spring is provided
with an adjusting collar to adjust spring preload. See Fig-
ure 55. Rotating the collar adjusts spring pressure. Rotate
the collar toward the spring to increase spring pressure.
CHAPTER THREE
with light
turn