Yamaha F100B F100C Outboards Factory Service Manual, Page 135Get this manual
Cylinder body Checking the piston ring grooves
1Measure the piston ring groovesReplace the piston if out of specificationPiston ring side clearance: Top ring a: 0.040.08 mm (0.00160.0031 in) Second ring b: 0.030.07 mm (0.00120.0027 in) Oil ring c: 0.030.15 mm (0.00120.0059 in)
Checking the crankshaft
1Measure the crankshaft journal diameter a, crank pin diameter b, and crank pin width cReplace the crankshaft if out of specification
S60C5860
Piston ring groove: Top ring a: 1.231.25 mm (0.04850.0492 in) Second ring b: 1.521.54 mm (0.05990.0606 in) Oil ring c: 2.512.53 mm (0.09890.0996 in)