2010 Polaris Sportsman 850 Service Manual, Page 152Get this manual

2010 Polaris Sportsman 850 Service Manual, Page 152

ENGINE Balance Shaft Installation See "Balance Shaft Timing" on page 5.551Balance shafts are identical but should be installed
until SINGLE dot on crankshaft gear is visibleAlign single dot of drive gear between two dots of balance gearAlign bearing
locating ring in groove on crankcase and fully seat the shaftVerify balance shaft timing is correct by comparing to illustration