Polaris 2012 Sportsman Forest 500 International, Service Manual

Page: 84 / 432

3.29
ENGINE
3
9923412 - 2012 Sportsman 400/500 and EFI Tractor Service Manual
© Copyright 2011 Polaris Sales Inc.
Cylinder Head Assembly
NOTE: Assemble the valves one at a time to
maintain proper order
1. Install new valve seals on valve guides.
2. Apply engine oil to valve guides and seats.
3. Coat valve stem with molybdenum disulfide grease.
4. Install valve carefully with a rotating motion to avoid
damaging valve seal.
5. Dip valve spring and retainer in clean engine oil and
install spring with closely spaced coils toward the
cylinder head.
6. Place retainer on spring and install valve spring
compressor. Compress spring only enough to allow
split keeper installation to prevent loss of spring
tension. Install split keepers with the gap even on both
sides.
7. Repeat procedure for remaining valve.
8. When all valves are installed, tap lightly with soft faced
hammer on the end of the valves to seat the split
keepers.
Valve Sealing Test
1. Clean and dry the combustion chamber area.
2. Pour a small amount of clean, high flash point solvent
into the intake port and check for leakage around each
intake valve. The valve seats should hold fluid with
no seepage.
3. Repeat for exhaust valves by pouring fluid into
exhaust port.
Valve Clearance Adjustment
NOTE: The exhaust valves share a common rocker
arm, and must be adjusted using two feeler gauges.
1. Insert .006” feeler gauge(s) between end of the valve
stem and adjuster screw(s).
2. Loosen locknut(s) and turn adjuster screw(s) until
there is a slight drag on feeler gauge(s). The Valve/
Clutch Adjuster Tool
(PA-44689) can be used to
adjust the engine valves.
NOTE: Both feeler gauges should remain inserted
during adjustment of each exhaust valve.
3. When clearance is correct, hold adjuster screw and
tighten locknut securely.
CAUTION
Wear eye protection during assembly.
VALVE CLEARANCE
.006” (.15 mm)
Feeler Gauge for Both Valves