1987 Honda Fourtrax TRX 250X Service Manual, Page 84Get this manual
CYLINDERPISTON Measure the connecting rod small end 1.0SERVICE LIMIT: 1710 mm (0.61 in)
PISTON INSTALLATION
Clean the piston ring grooves thorougly and install the piston ringsNOTE
Avoid piston and piston ring damage during installationInstall the piston rings with the marking facing upDo not mix the top and second rings
Space he piston ring end gaps 120 degrees apart Do not align the gaps in the oil rings Iside rails)After jnstallat ion, the rings should be free to rot8te jn the ring grooves(1)