2005-2009 Honda TRX400EX/TRX400X Service Manual, Page 150Get this manual
CYLINDERPISTON PISTON INSTALLATION Place clean shop towel over the crankcase to revent the piston pin li from fa ll ing in to th crankcaseApp ly mo lybdenum il sol ution to th connecting rod small end inner surface and piston pin outer su rface
Apply engine oi to he piston pin holes, Install the piston with the "IN" mark towa rd the intake sid and insert the piston pin through the piston and connectin rod Do flat align the cliP end gap wl[h rhe