44
Performance Tips
Operating a high performance snowmo-
bile requires a special attention that is not
required by a low performance snowmo-
bile. Often, a minor adjustment will
result in a large increase in performance.
This section is intended to highlight
minor conditions that adversely affect
performance and the adjustments needed
to correct them. Be sure, however, to
thoroughly read and understand this
entire manual especially the section on
spark plugs, track tension and alignment,
and suspension.
DRIVE CLUTCH/DRIVEN
CLUTCH OFFSET
If premature drive belt wear is experi-
enced or if the drive belt turns over, off-
set must be checked. Also, offset must be
checked whenever either the drive clutch
or driven clutch is serviced.
Checking Offset
1. Remove the left-side access panel.
2. Remove the drive belt.
NOTE: Use a straightedge that is
approximately 470 mm (18.5 in.)
long, 20 mm (0.79 in.) wide, and 4
mm (0.16 in.) thick.
3. Measure the offset (A) between the
drive clutch and the driven clutch.
Sheave offset must be within 58.1-
61.1 mm (2.29-2.41 in.). If adjust-
ment is needed, proceed to step 4.
SNO-720
4. If offset adjustment needs to be
made, remove the driven clutch and
add shims (p/n 8JP-RA448-00): 1
mm (0.04), (8JP-RA449-00): 2 mm
(0.08) to increase the offset or
remove shims to decrease the offset.
5. Once the correct offset is reached,
install driven clutch and tighten cap
screw to 60 N-m (6.0 kg-m, 43 ft-
lb).
DRIVE BELT POSITION
Drive belt length, condition, and position are
all important for peak performance. To
check and adjust drive belt, remove the belt
guard; then use the following procedure.
NOTE: Removing/adding shim
washers may be done by the snow-
mobile owner if qualified to do so.
If the owner does not feel qualified,
take the snowmobile to an autho-
rized Yamaha Snowmobile dealer
for this service. This service is at
the discretion and expense of the
snowmobile owner.
1. Turn the engine off; then open the
left access panel.
2. Make sure the drive belt is posi-
tioned from 1.5 mm (0.06 in.) above
the edge (A) of the driven clutch
sheaves to 0.5 mm (0.02 in.) below
the edge (B).
SNO-774
WARNING
If the belt is not positioned cor-
rectly, the clutch engagement
speed will be changed. The snow-
mobile may move unexpectedly
when the engine is started.
U8KCS1E0.book Page 44 Tuesday, May 16, 2017 5:42 PM