18
OM944T 2/11
Servicing
SP7. VALVE CLEARANCES
1. Readjust valve clearance after fi rst 50 hours of
operation. Check valves every 500 hours thereafter.
2. Check the valves when the engine is cold.
3. Rotate the crankshaft in a clockwise direction in the
front 180
0
to bring each piston to the top dead center
on the compression stroke. Top dead center (TDC) is
when notch on the pulley aligns with the pointer and
the two valves on cylinder No. 1“rock”. Rocking is
when the rocker arms (for the two valves on a given
cylinder) are moving in opposite directions, one up
closing the valve and one down opening the other
valve. The moment when the two rocker arms are
exactly aligned with each other is when they “rock”.
Figure 8: Timing Mark
4. Measure the valve clearance for each of the valves,
with a feeler gauge, in the fi ring order (1-3-4-2).
Standard valve clearances for a cold engine are:
Intake (IN)........................0.0098 in. (0.25 mm)
Exhaust (EX)....................0.0098 in. (0.25 mm)
5. To adjust valve clearance, loosen the lock nut on the
adjustment screw. Insert a feeler gauge between the
rocker arm and the valve stem cap. Adjust, while
measuring the clearance, until the feeler gauge slides
with a slight drag. Tighten the lock nut and recheck
the clearance (
Figure 9
).
Figure 9: Valve Adjustment
6. Adjust the remaining valves.
7. Replace the rocker arm cover.
Tightening Cylinder Head Bolts Order
17 bolts total, Tightening Torque:
113 to 123 N•m (11.5 to 12.5 kgf•m)
[83.2 to 90.4 lbf•ft]
Front
