Polaris 2012 Sportsman Forest 500 International, Service Manual

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3.21
ENGINE
3
9923412 - 2012 Sportsman 400/500 and EFI Tractor Service Manual
© Copyright 2011 Polaris Sales Inc.
10. Slide camshaft out the PTO side of the cylinder head.
Automatic Compression Release Removal /
Inspection
NOTE: The automatic compression release
mechanism can be inspected and serviced without
removing the camshaft from the cylinder head. The
actuator ball in the camshaft is not replaceable.
Replace the camshaft as an assembly if the actuator
ball is worn or damaged.
1. Check release lever shaft (A) for smooth operation
throughout the entire range of rotation. The spring
(B) should hold the shaft weight against the stop pin.
In this position, the actuator ball (C) will be held
outward in the compression release mode.
2. Remove release lever shaft and return spring.
3. Inspect shaft for wear or galling.
4. Inspect lobe on end of release lever shaft and actuator
ball for wear and replace if necessary.
Automatic Compression Release Installation
1. Slide spring onto shaft.
2. Apply engine oil to release lever shaft.
The actuator ball must be held outward to allow installation
of the release lever shaft.
If Camshaft is Removed From Engine:
3. Turn the camshaft until the actuator ball is in the
lowest position and install the release lever shaft.
If Camshaft is Installed in the Engine:
4. Use a small magnet to draw the actuator ball outward,
or rotate the engine until the cam lobes face upward
and install release lever shaft.
5. Position camshaft as shown at the bottom of Figure
3.21 .
6. Place arm of spring under stop pin as shown and push
release lever inward until fully seated. Do not pre-
wind the spring one full turn or the compression
release will not disengage when the engine starts.
Check operation of mechanism as outlined in Step 1
of Removal (above).

NOTE: When shaft is properly installed, actuator ball
will be held in the “out” position. It is important to note
that spring pressure is very light.
Decompressor Shaft
Decompressor Ball
Retainer Sleeve
B
A
C
Stop Pin
Spring in relaxed position
Figure 3.21