1985-1995 Polaris ATV and Light Utility Hauler Service Manual, Page 319Get this manual
ENGINES Magnum Engine Assembly 3Measure the distance from the PTO crankcase mating surface to the main bearing using dial caliper and straight edgeSubtract the thickness of the straightedge and record
Measure the distance from the magneto crankcase mating surface to the main bearing using the same methodRemember to subtract the straightedge from the measurement, and record5Add the readings obtained in step and 46Subtract the crankshaft width measured in step from the figure obtained in step 57Subtract the thickness of the existing shim from the result of step to determine if different shim is needed7.95