1987 Honda Fourtrax TRX 250X Service Manual, Page 83Get this manual
CYLINDERPISTON Measure the piston ring-ta-groove clearanceSERVICE LIMITS :
TOP: .80 mm (0 .032 in) SECONO: .80 mm (0 032 inl
Insert each piston ring squarely into the cylinder and measure the ring end gapNOTE
Push the rings int he cylinder with the top of the piston to be sure they are squarely in the cylinderSERV ICE LIMIT:
TOPISECOND.50 mm (0 .020 in)