Yamaha MM600D, Manual

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CHAPTER TEN
Check for sheared cogs (Figure 13) caused by vio-
lent primary sheave engagement. This is an indica-
tion of a defective or improperly installed primary
sheave.
5. Replace a worn or damaged belt immediately. Always
carry a spare belt on the snowmobile for emergency pur-
poses.
Drive Belt Height Adjustment
For a 1: 1 sheave ratio to occur, the drive belt must move
to the outer edges of the secondary sheave (A, Figure 14)
when the sheave halves are closed together (neutral posi-
tion). However, because friction gradually reduces the
width of the drive belt, a narrow belt will not move to the
outer edges, thus preventing the sheaves from shifting to a
1: 1
ratio. To compensate for belt wear, reduce the distance
between the sheave halves by adding shim washers
Figure
14) onto the sliding sheave half retaining bolts.
Perform this procedure whenever installing a new drive
belt.
1. Open and secure the hood.
2. Remove the belt guard,
3. Check that the drive belt is resting at the top of the sec-
ondary sheave (A, Figure 14).
4.
Measure the distance from the top of the drive belt to
the edge of secondary sheave (Figure 15). The belt
should be from 1.5 (0.06 in.) above the flange edges
to 0.5 mm (0.02 in.) below the flange edges.
5. To adjust the drive belt height in the secondary sheave,
proceed as follows:
a. Remove the secondary sheave as described in this
chapter.
b. On models so equipped, remove the cover plate
(2,
Figure 6) on the sliding sheave half.
Shim