2010 Polaris Sportsman 850 Service Manual, Page 148Get this manual

2010 Polaris Sportsman 850 Service Manual, Page 148

ENGINE ENGINE ASSEMBLY Crankcase PreparationUpper 1Refer to Oil Flow Diagram (page 5.4) and trace the oil path through the
MAG Exhaust Oil ring rail Oil ring rail Piston Ring Installation Apply clean engine oil to ringsCheck installed gap before
installing on pistonClean accumulated carbon from ring grooves and oil ring lube holes if piston has been in service1Place
oil control ring expander in oil ring grooveTips of expander gap (A) must face piston crown so scraper edge (B) of expander
faces piston skirtRotate expander in groove until butt ends are on intake side of pistonEnds must butt squarely together
and must not overlapInstall bottom rail first, then top rail with end gap located as shown at rightOil Control Ring Installation
Top Rail 2nd ring gap Top ring gap "0" mark on top Barrel face Bottom Rail Expander Undercut facing down (piston skirt) Notched