Piston Ring Installation - Polaris Sportsman 400 Service Manual

ENGINE

PISTON RING INSTALLATION

NOTE: Apply clean engine oil to all ring surfaces and ring lands. Always check piston ring installed gap before
rings are installed on piston. See page 3.43. If the piston has been in service clean any accumulated carbon
from the ring grooves and oil control ring holes.
1. Place the oil control ring expander in oil ring groove with the end gap facing forward. The expander has no up
or down marking and can be installed either way. The ends should butt squarely together and must not
overlap.
2. Install the oil ring top rail.
NOTE: The top rail has a locating tab to prevent rota-
tion. The tab must be positioned in the notch on the
side of the piston as shown (A).
3. Install the bottom rail with the gap at least 30° from
the end of the expander on the side opposite the
top rail gap.(See Ill.).
4. Install the second ring with the "R" mark facing up.
Position the end gap toward the rear (intake) side
of the piston.
5. Install the top ring (chrome faced) with the "R"
mark facing up and the end gap facing forward
(toward the exhaust). (See Ill.).
6. Check to make sure the rings rotate freely in the
groove when compressed.
3.64
- projex@inbox.lv -
A
Ring Profile
Mark up
Second
Mark up
Top