2005-2009 Honda TRX400EX/TRX400X Service Manual, Page 132Get this manual
CYLINDER HEADVALVE If th con act area is to high on th va lve, he seat must be lowered using 320 lat cutterIf the contact area is too low on he valve, he seat must be raised using 60" interior cu tter
CONTACT TOO HIGH
OLDSEAT
Reiace (he sear With 45 culter whenever valve guide IS repace d
Use 45 seat cutter to re ove any ro ughness or irregularities rom the seat
TOOLS: Seat cutter, 35 mm (45" IN) Seat cutter, 29 mm (45 EX) Cutter holder, 5.5 mm
ROUGHN ESS
07780-0010400 077800010300 07781-0010101
or equivalent commercially available in U.S.A