Honda CBR125R, Owner'S Manual

Page: 209 / 430

CYLINDER HEAD/VALVES
8-21
Reface the valve
seat with a 45
°
cutter when a valve
guide is replaced.
Use a 45
°
cutter, remove any roughness or irregu-
larities from the seat.
Using 32
°
cutter, remove the top 1/4 of the existing
valve seat material.
Using 60
°
cutter, remove the bottom 1/4 of the old
seat.
Remove the cutter and inspect the area you have
just removed.
Using a 45
°
cutter, cut the seat to proper width.
Make sure that all pitting and irregularities are
removed.
Refinish if necessary.
TOOLS:
Seat cutter, 24 mm (45
°
EX) 07780-0010600
Seat cutter, 29 mm (45
°
IN) 07780-0010300
Cutter holder, 5.0 mm 07781-0010400
VALVE SEAT CUTTER
ROUGHNESS
TOOLS:
Flat cutter, 27 mm (32
°
EX) 07780-0013300
Flat cutter, 30 mm (32
°
IN) 07780-0012200
Cutter holder, 5.0 mm 07781-0010400
OLD SEAT WIDTH
32
°
TOOLS:
Interior cutter, 26 mm (60
°
EX) 07780-0014500
Interior cutter, 30 mm (60
°
IN) 07780-0014000
Cutter holder, 5.0 mm 07781-0010400
60
°
OLD SEAT WIDTH
STANDARD SEAT WIDTH:
0.90 – 1.10 mm (0.035 – 0.043 in)
SEAT WIDTH
45
°