Polaris SPORTSMAN 400 2003, Service Manual, Page: 77 / 274

ENGINE
3.26
A
18. Clean cylinder head, valves, and camshaft oil
supply passage (A) thoroughly.
19. If oil passage blind plug was removed, apply
Crankcase Sealant (PN 2871557) or equivalent
sealer to the threads and install, torquing to 8 ft.
lbs. (11 Nm). CAUTION: Do not allow sealant to
enter oil passage.
20. Spray electrical contact cleaner into oil passage
and dry using compressed air.
CYLINDER HEAD ASSEMBLY
CAUTION: Wear eye protection during 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.
Enfocus Software - Customer Support