1985-1995 Polaris ATV and Light Utility Hauler Service Manual, Page 320Get this manual
ENGINES Magnum Engine Assembly Counter Balancer 1Make sure all bearings are firmly seated in the crankcase2Measure the width of the counter balancer shaft at the bearing seats with dial caliper or micrometer, and record reading3Measure the distance from the PTa crankcase mating surface to the bearing using dial caliper and straight edgeSubtract the thickness of the straightedge and record4Measure the distance from the magneto crankcase mating surface to the bearing using the same method5Add the readings obtained in step and 46Subtract the counter balancer shaft 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 needed
Pump Shaft
1Make sure the pump shaft bearing is firmly seated in the Magneto side crankcase2Measure the distance from the magneto crankcase mating surface to the bearing using dial caliper and straight edgeSubtract the thickness of the straightedge and record3Install the gear on the oil pump and measure the width of the pump and gearSubtract this measurement from the measurement recorded in step 24Subtract the thickness of the existing shim from the result of step to determine if different shim is needed