1985-1987 Honda TRX 250 Fourtrax 250 Service Manual, Page 77Get this manual
CYLINDERPISTON Measure the diameter of the piston 10 mm from the bottom and 90 to the piston pin holeSERVICE LIMIT: 73.90 mm 12.909 inl
Calculate the piston-ta-cylinder clearance(Refer to page 72 for cylinder bore inspect ion SERVICE LIMIT0.10 mm (0.0041n)
Measure the piston pin hole 1.0SERVICE LIMIT19.04 mm (0.750 in) Measure the 0.0of the pist on pin SERVICE LIMIT18.96 mm (0 .747 inl Calculate the piston-ta-piston pin clearanceSERVICE LIMIT: .02 mm (0.001 inl