Honda CRF450R 2020, Owner'S Manual & Competition Handbook

Page: 85 / 199

80
Servicing Your Honda
Valve Clearance
1. Remove the crankshaft hole cap (1).
2. Remove the spark plug (page 78).
3. Remove the cylinder head cover (page 79).
4. Rotate the crankshaft by turning the primary
drive gear bolt (2) clockwise until “T” mark (3)
on the primary drive gear aligns with the index
mark (4) on the clutch cover. In this position,
the piston may either be on the compression or
exhaust stroke at TDC. If the primary drive
gear passed the “T” mark, rotate the primary
drive gear bolt clockwise again and align the
“T” mark with the index mark.
Make sure that the decompressor weight (5) is
upper position.
5. Check the timing marks (6) on the cam
sprocket aligns with the camshaft holder
mating surface (7) of the cylinder head.
6. The inspection must be made when the piston
is at the top of the compression stroke when
both the intake and exhaust valves are closed.
This condition can be determined by moving
the rocker arms (8).
Positioning At TDC On The
Compression Stroke
(1) crankshaft hole cap
(1)
(2) primary drive gear bolt
(3) “T” mark
(4) index mark
(5) decompressor weight
(2)
(3)
(4)
(5)
crankshaft side: camshaft side:
(6) timing marks
(7) camshaft holder mating surface
(8) rocker arms
(6)
(7)
(8)
(8)