1986 Ski-Doo Factory Shop Manual, Page 211Get this manual
Section 02 ENGINE Sub-section 10 (ENGINE DIMENSIONS MEASUREMENT)
ENGINE DIMENSIONS MEASUREMENT
This section cover all 1986 engine types: 247, 253,377,447,462,467,503,532,537
CYLINDER TAPER
253 Engine type
Not applicable
Measuring 16 mm (58") from top of cylinder with cylinder gauge, check if the cylinder out of round is more lhan the specified dimensionIf larger, cylinder should be rebored and honed or should be replaced
GUdOJeon
direction
ALL OTHERS 1986 ENG INES
MAXIMUM: 0.08 mm (.003")
.compare cylinder diameter 16 mm (518") from top of cylinder to just below its Intake port areaOn rotary valve engines, measure just below auxiliary transfer port, facing exhaust port If the difference exceeds 0.08 (,003' ') the cylinder should be rebored and honed or should be replacedA001001021