Honda CRF450R Owner's Manual page 79

Valve Clearance
Camshaft Installation
1. Install the newly selected shims (1) on the
valve spring retainers (2).
NOTICE
Do not let the shims fall into the crankcase.
(1)
(2)
(2)
(1)
(1) shims
(2) valve spring retainers
2. Apply molybdenum disulfide oil (a mixture of
1/2 engine oil and 1/2 molybdenum disulfide
grease containing more than 3% molybdenum
disulfide additive) to the following parts.
– camshaft cam lobes
– each valve lifter outer surface
– plunger whole surface
72
Servicing Your Honda
3. Install each valve lifter (3) in their original
location into the cylinder head (4).
(3)
(4)
(3) valve lifters
(4) cylinder head
4. Check the operation of the plunger (5) by
turning the decompressor weight (6) with your
finger; The plunger should be retracted and
protruded smoothly.
(6)
(5)
(5) plunger
(6) decompressor weight
If the operation is not smooth, refer to an official
Honda Service Manual (page 162) for
decompressor disassembly or see your dealer.
5. Make sure the piston is at TDC on the
compression stroke (page 67).
6. Install the camshaft (7) onto the cylinder head
with intake cam lobes (8) facing up as
illustrated below.
(8)
(7)
(7) camshaft (8) intake cam lobes
7. Install the cam chain (9) over the cam sprocket
(10).
While holding the left camshaft bearing (11) to
the left fully, install the camshaft (7) onto the
cylinder head (4).
(7)
(10)
(9)
(11)
(4) cylinder head (10) cam sprocket
(7) camshaft (11) left camshaft bearing
(9) cam chain
(4)