Honda CRF450RX 2020 Owner's Manual & Competition Handbook page 86

Valve Clearance Inspection
1. Set the piston at TDC on the compression
stroke (page 80).
2. Measure the intake valve clearances by
inserting a feeler gauge (1) between the intake
rocker arms (2) and camshaft cam lobes (3).
Be careful not to damage the intake rocker arms.
(3)
(3) (1)
(2)
(1) feeler gauge (3) camshaft cam lobes
(2) intake rocker arms
Valve Clearance:
IN: 0.005 ± 0.001 in (0.13 ± 0.03 mm)
3. Measure the exhaust valve clearances by
inserting a feeler gauge (1) between the
exhaust rocker arms (4) and shims (5).
(5)
(2)
(4)
(1)
(5)
(1)
(1) feeler gauge
(4) exhaust rocker arms
Valve Clearance:
EX: 0.011 ± 0.001 in (0.28 ± 0.03 mm)
(3)
If intake valve clearance and exhaust valve
clearance need adjustment, see Camshaft Removal
(this page) and select the correct shim for each
valve.
1. Make sure the piston is at TDC on the
(4)
2. Remove the cam chain tensioner lifter cover
(1)
(5)
(1) cam chain tensioner lifter cover bolt
(2) sealing washer
(4)
(5) valve shims
Valve Clearance
Camshaft Removal
compression stroke (page 80).
Record the intake valve and exhaust valve
clearances (this page).
bolt (1) and sealing washer (2).
(2)
Servicing Your Honda
(1)
(cont'd)
81