Honda CRF450R 2009 Service Manual page 95

Clean the valve shim contact area in the valve lifter with
compressed air.
Measure the shim thickness and record it.
Seventy-three
Calculate the new shim thickness using the equation
dIfferent thlCk.ness below
shims
are
available
from 1.200
mm
10
A=(B-C)+D
3.000 mm
In
A: New shim thickness
Increments
of
0_025mm,
B: Recorded valve clearance
C: Specified valve clearance
D: Old shim thickness
Make sure of the correct shim thickness by
measuring the shim using a micrometer.
Reface the Intake valve seat if carbon deposits
result in a calculated dimenSion of over 2.450 mm .
Reface the exhaust valve seal if carbon deposits
result in a calculated dimension of over 3.000 mm.
Ins/all the shIms
In
Inslall the newly selected shims on the valve spring
the"
ongmal retainers
locatIOns
MAINTENANCE
GGG
1.80 mm 1.825 mm 1.85 mm 1.875 mm
4-15