Valve Clearance - Honda CRF450X 2020 Owner's Manual & Competition Handbook

Valve Clearance

Refer to Important Safety Precautions on page 31.
Excessive valve clearance will cause noise and
eventual engine damage. Little or no clearance will
prevent the valve from closing and cause valve
damage and power loss. Check valve clearance
when the engine is cold at the intervals specified in
the Maintenance Schedule (pages 33, 34).
The checking or adjusting of the valve clearance
should be performed while the engine is cold.
The valve clearance will change as engine
temperature rises.
Cylinder Head Cover Removal
Before inspection, clean the engine thoroughly to
keep dirt from entering the engine.
1. Remove the seat and fuel tank (pages 43, 45).
2. Disconnect the breather tube (1) and spark
plug cap (2).
(2)
(1) breather tube (2) spark plug cap
3. Remove the cylinder head cover socket bolts
(3), rubber seals (4), cylinder head cover (5)
and spark plug hole packing (6).
(6)
(3)
(1)
(3) cylinder head cover socket bolts
(4) cylinder head cover rubber seals
(5) cylinder head cover
(6) spark plug hole packing

Valve Clearance

(3) (5)
(4)
81
Servicing Your Honda