2007 Polaris Two Stroke Snowmobile Workshop Repair manual, Page 61Get this manual
MAINTENANCE Make sure the thermostat opens and stays open! Cycle the RPM from idle to enough RPM (3500) to get coolant to flow but not enough RPM to engage the clutchThis allows air to bleed from the rear crossover tubeIt is important to get enough coolant flow to purge the air from the front close-off cooler and observe this air reaching the bottleNOTE: Once the thermostat is open tip the snowmobile slightly on its right side and cycle the RPM from idle to enough RPM (4000) to get coolant to flow but not enough RPM to engage the clutchThen tilt the machine slightly on its left side so that the coolant bottle is the highest point in the cooling system and cycle the RPM from idle to enough RPM (4000) to get coolant to flow but not enough RPM to engage the clutchor tightNormal hand installation will be an indication of the recommended interference fitIf the bearing falls out of the case when the case is inverted, or if the crankcase bearing surface is severely galled or damaged, the case should be replacedNOTE: Crankcase bearing interference fit is .001.002" (.026-.051mm)