Honda CRF250X 2007 Owner's Manual & Competition Handbook page 72

2. Rotate the crankshaft by turning the primary
drive gear bolt (2) clockwise until aligning the
punch mark (3) on the primary drive gear with
the "∆" 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 "∆"
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 lock bolt 360° and realign
the punch mark to the "∆" mark.
(2)
(3)
(2) primary drive gear bolt (4) "∆" mark
(3) punch mark
(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 lobe (3).
(4)
(1) feeler gauge
(2) valve lifters
(3) intake cam lobe
(5)
(1)
(3)
(2)
Valve Clearance
2. Measure the exhaust valve clearance by
inserting a feeler gauge (1) between the
exhaust rocker arm (4) and shims (5).
(5)
(1)
(1) feeler gauge
(4) exhaust rocker arm
(5) exhaust valve shims
Valve Clearances:
IN: 0.005 ± 0.001 in (0.12 ± 0.03 mm)
EX: 0.011 ± 0.001 in (0.28 ± 0.03 mm)
If intake valve clearance and exhaust valve
clearance need adjustment, see Camshaft
Removal (page 68) and select the correct shim for
each valve.
Servicing Your Honda
(4)
67