1983 Ski-Doo Shop Manual, Page 122Get this manual
SECTION 02 ENGINE SUB-SECTION 07 (ENGINE TOLERANCES MEASUREMENT)
a) Measure crankcase halves as illustrated (M, and M2)A standard compressed crankcase gasket will have 0.30 mm (,012") thickness (M3lAdd these measurements to obtain dimension "A"
NOTE: The 247 engine type has one distance ring on PTO side and adjustment shims on MAG sideThe 277 engine type has one distance ring on PTO side and one distance ring and adjustment shims on MAG side
c) From dimension A, subtract dimension BThe result is the actual crankshaft end-play that must be within specificationIf the result is over specification, add adjustment shim(s)If the result is under specification, remove adjustment shim(s)