32
NOTE: A long T50 ball head torx
bit will be needed to remove or
install the torx screws.
XM489
4. Loosen the jam nut.
5. Turn the chain tension adjustment
bolt clockwise until it is finger tight;
then loosen it 1 1/2 turns.
0747-831
6. While holding the bolt with a
wrench, tighten the jam nut to 2.4
kg-m (18 ft-lb).
7. Install the resonator and secure
using the existing gasket, spring, and
cap screws. Tighten the screws to
1.2 kg-m (9 ft-lb) then to 2.4 kg-m
(18 ft-lb) in a crisscross pattern.
NOTE: Apply a small amount of
high temperature anti-seize lubri-
cant to the threads of the screws.
8. Install the turbo heat shield and
secure using the existing screws and
washers. Tighten securely.
9. Install the hood and access panels.
Drive Belt
The drive belt transfers power from the
drive clutch to the driven clutch. If the
belt is worn, cracked, or stretched, maxi-
mum power will not be transmitted and
the belt could also fail and therefore must
be replaced. Periodic checks (at least
once a month under normal usage) of two
drive belt specifications are essential.
1. Measure the outside circumference of
the drive belt. The belt should be
within 1118-1126 mm (44.0-44.3 in.).
2. Measure the outside width of the drive
belt. The belt should be at least 34.5
mm (1.36 in.) on a new belt or 32.5
mm (1.28 in.) on a broken in belt.
3. Check the belt for cracking, fraying, etc.
If any of the specifications or conditions
are unsatisfactory, replace the drive belt.
NOTE: Drive belts should be pur-
chased from an authorized Yamaha
Snowmobile dealer, as Yamaha drive
belts are made to exact specifica-
tions and of quality material. Belts
made by other manufacturers may
not be of the same specifications or
quality and, therefore, usage could
result in poor performance and pre-
mature belt failure.
NOTE: Before starting the snow-
mobile in extremely cold tempera-
tures, the drive belt should be
removed and warmed up to room
temperature. Once the drive belt is
at room temperature, install the
drive belt.
Also, new drive belts have a break-in
period of 40 km (25 miles). After installing
a new drive belt, drive the snowmobile for
40 km (25 miles) at 3/4 throttle or less. By
revving the engine up and down (but not
exceeding 97 km/h [60 mph]), the exposed
cord on the side of a new belt will be worn
down. This allows the drive belt to gain its
optimum flexibility and will extend drive
belt life.
Jam Nut
Adjustment Bolt
Chain Adjuster
CAUTION
Never run the engine with the drive
belt removed. Excessive revving of the
engine could result in serious engine
damage and drive clutch failure.
U8KCS1E0.book Page 32 Tuesday, May 16, 2017 5:42 PM