2004-2005 Honda TRX450R Factory Sevice Manual, Page 152Get this manual
CYLINDER HEADIVALVE Use 45 seat cutter to remove any roughness or rreg ularit ies ro the seatTOOLS: Seat cutter, 35 mm (45 INSeat cutter, 33 mm (450 EX) Cutter holder, 5.5 mm
ROUGHNESS
077800010400 07780-0010800 077810010101
or equivalent commercially available in U.S.A
Usi ng 32 flat cutter, remove 14 of the ex ist ing alv seat materialTOOLS: Flat cutter, 36 mm (32 INFlat cutter, 33 mm (32 EX) Cutter holder, 5.5 mm
07780-0013500 07780-0012900 07781-0010101