Honda CRF250R 2005 Owner's Manual page 60

Valve Clearance
3. Rotate the crankshaft by turning the primary
drive gear lock bolt (3) (crankshaft) clockwise
until aligning the "punch" mark (4) on the
primary drive gear with the index mark (5) 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 lock 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 (6). 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 index mark.
(3)
(4)
(3) primary drive gear lock bolt
(4) "punch" mark
(6) exhaust rocker arm
56
Servicing Your Honda
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).
(1) feeler gauge
(2) valve lifters
(5)
(3) intake cam lobe
(5) index mark
(6)
(1)
(3)
2. Measure the exhaust valve clearance by
inserting a feeler gauge (1) between the
exhaust rocker arm (4) and shim (5).
(5)
(2)
(1)
(1) feeler gauge
(4) exhaust rocker arm
(5) exhaust valve shim
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 57) and select the correct shim for
each valve.
(4)