Honda CRF450R 2006 Owner's Manual page 62

Valve Clearance
4. Remove the cam sprocket bolt (4).
Rotate the primary drive gear bolt (crankshaft)
clockwise one turn and remove the other
sprocket bolt and cam sprocket (5). Then
attach a piece of wire to the cam chain to
prevent it from falling into the crankcase.
NOTICE
Do not let the bolts, sprocket and cam chain (7)
fall into the crankcase.
(6)
(5)
(4) cam sprocket bolts
(5) cam sprocket
(6) cam chain
58
Servicing Your Honda
5. Make sure the piston is at TDC (Top Dead
Center) on the compression stroke. Loosen the
camshaft holder assembly bolts (7) in a
crisscross pattern in 2 – 3 steps.
Remove the camshaft holder assembly bolts,
camshaft holder assembly (8), intake valve
lifters (9) and shims (10).
As you remove the camshaft holder assembly,
the intake valve lifter and the intake valve
shim may be sticking in the camshaft holder
assembly.
Keep the intake valve lifters and the shims so as
to allow identification of the originally installed
(4)
location such as intake or exhaust, right or left.
(7)
(8)
(7) camshaft holder assembly bolts
(8) camshaft holder assembly
NOTICE
Do not let the valve lifters and shims fall into the
crankcase.
(8)
(10)
(8) camshaft holder assembly
(9) intake valve lifters
(10) shims
6. Remove the valve shims.
(9)