1974 Ski-Doo Shop Manual, Page 232Get this manual
1974 ONE CYLINDER ENGINE Nominal dimension of cylinder bore Engine Type 247 302
TECHNICAL DATA
Cylinder out of round
Measuring Y2" (13 mm) from top of cylinder with cy linder gauge, check if the cylinder out of round is more than .002" (0.05 mm)If larger, cylinder should be rebored and honed or should be replaced
Standard 2.7165" 169 mml 2.9921" 176 mml
1st oversize 2.7362" 169.5 mmI 3.0118" 176.5 mml
2nd oversize 3.0315" 177 mml