1986-1987 Honda TRX350 FourTrax 4X4, 1987-1989 TRX350D Foreman 4X4 Service Manual, Page 89Get this manual
CYLINDERPISTON Inspect the top of the cylinder for warpageSERVICE LIMIT: 0.10 mm (0.004 in)
REMOVAL
Remove the piston pin clip with pliers
Do not let the clips fall into the crankcase
Press the piston pin out of the piston and remove the piston
PISTON RING INSPECTION
Remove the piston rings
Do not damage the piston rings during removal