Shim Selection - Honda CRF450R Manual Del Propietario Y Guía De Competiciones

Valve Clearance

Shim Selection

1. Clean the valve shim contact area in the valve
lifter (1) with compressed air.
(1)
(1) valve lifter
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Servicing Your Honda
2. Measure the shim thickness with a micrometer
and record it.
Seventy-three different shims (2) are available
in 0.025 mm thickness intervals, from 1.200
mm (the thinnest) to 3.000 mm (the thickest).
(2)
(2) shim
3. Calculate the new shim thickness using the
equation below.
A = (B – C) + D
A: New shim thickness
B : Recorded valve clearance
C : Specified valve clearance
D: Old shim thickness
• Make sure of the correct shim thickness by
measuring the shim with a micrometer.
• Reface the intake valve seat if carbon deposits
result in a calculated dimension of over 2.450
mm.
Reface the exhaust valve seat if carbon deposits
result in a calculated dimension of over 3.000
mm.
1.80 mm 1.825 mm 1.85 mm 1.875 mm