Honda CRF450X 2005 Service Manual page 204

CYLINDER HEADIV ALVES
Reface the sear
Use a 45° seat cutter, remove any roughness or
WIth
a
45~cutte, irregularities from the seat.
whenever B valve
guide
is
rep/aced.
TOOLS:
Seat cutter, 35 mm liN)
Seat cutter, 33 mm (EX)
Cutter holder, 5.5 mm (IN)
Cutter holder, 5.0 mm (EX)
07780·0010400
07780·0010800
07781·0010101
07781-0010400
or equivalent commercially available in U.S.A .
Use a 32° flat cutter, remove 1/4 of the exist ing
valve seat material.
TOOLS:
Flat cutter, 36 mm (IN)
Flat cutter. 33 mm (EX)
Cutter holder, 5.5 mm (IN)
Cutter holder, 5.0 mm (EX)
07780-0013500
01780·0012900
07781·0010101
07781·0010400
or equivalent commercially available in U.S.A.
Use a 60° interior cutter, remove 1/4 of the existi ng
valve seat materia l.
TOOLS:
Interior cutter, 37.5 mm (IN)
Interior cutter, 34 mm (EX)
Cutter holder, 5.5 mm (IN)
Cutter holder, 5.0 mm
(EX)
07780-0014100
07780-0014700
07781·0010101
07781 -0010400
or equivalent commercially available in U.S.A.
-
ROUGHNESS
/~EATWIDTH
32°~
-~~...J~OLD
~)SEAT WIDTH
Using a 45° seat cutter, cut the seat t o proper width.
~=================~
Make sure all pitting and irreg ularities are removed.
9-32
Refinish if necessary.
STANDARD:
IN : 1.1 - 1.3 mm (0.04 - 0.05 in)
EX: 1.3 - 1.5
mm
(0.05 - 0.06
in)
, ' '",
-------' 45°L
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