2008 Yamaha WaveRunner FX SHO / FX Cruiser SHO Service Manual, Page 228Get this manual
Crankcase, connecting rod, and piston
3Measure: Piston ring grooves Out of specification Replace the pistonNOTE: Before measuring the piston ring grooves, eliminate any carbon deposits from the piston ring groovesPiston ring groove: Top ring a: 1.211.23 mm (0.04760.0484 in) 2nd ring b: 1.211.23 mm (0.04760.0484 in) Oil ring c: 2.512.53 mm (0.09880.0996 in)