2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 82Get this manual
ENGINE (300) 6Add the readings recorded in Step and Step and record below
Balancer Shaft End Play Adjustment
NOTE: The balancer shaft end play measurement procedure is the same as that outlined for the crankshaftThe exception is that measurements are taken to the balancer shaft bearings in the case, rather than the crankshaft main bearings, and the width of the balancer shaft is measured, not the crankshaft12Make sure the counter balance shaft bearings are firmly seated in each crankcaseMeasure the distance from the Mag crankcase mating surface to the balance shaft bearing using dial caliper and straight edgeSubtract the thickness of the straightedge and record
Total Case Width_ 7Measure the width of the crankshaft at the bearing seats (or to the outside of bearing if bearing is on the crankshaft as shown) with micrometer or dial caliper and record