Servicing Your Honda
67
Valve Clearance
(5)
(5) exhaust rocker arm
Valve Clearance Inspection
1. Measure the intake valve clearance by
inserting a feeler gauge (1) between the valve
lifters (2) and intake cam lobes (3).
(1)
(3)
(2)
(1) feeler gauge
(2) valve lifters
(3) intake cam lobes
Valve Clearance:
IN
:
0.006 ± 0.001 in (0.16 ± 0.03 mm)
2. Measure the exhaust valve clearance by
inserting a feeler gauge (1) between the
exhaust rocker arm (4) and shims (5).
(4)
(1)
(5)
(1) feeler gauge
(4) exhaust rocker arm
(5) exhaust valve shims
Valve Clearance:
EX:
0.011 ± 0.001 in (0.28 ± 0.03 mm)
If intake valve clearance and exhaust valve
clearance need adjustment, see
Camshaft Holder
Assembly Removal
(page 68) and select the
correct shim for each valve.
2. Rotate the crankshaft by turning the primary
drive gear bolt (2) clockwise until the
punch mark (3) on the primary drive gear
aligns with the index mark (4) on the right
crankcase cover. In this position, the piston
may either be on the compression or exhaust
stroke. If the crankshaft passed the punch
mark, rotate the primary drive gear bolt
clockwise again and align the punch mark
with the index mark.
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 exhaust rocker arm (5). If it is free, it is
an indication that the valves are closed and
that the piston is on the compression stroke.
If it is tight and the valves are open, rotate the
primary drive gear bolt 360° and realign the
punch mark with the index mark.
(2)
(4)
(3)
(2) primary drive gear bolt
(3) punch mark
(4) index mark
17 CRF450X̲31MEY710.indb 67
17 CRF450X̲31MEY710.indb 67
2016/06/08 11:45:49
2016/06/08 11:45:49