OM843NW2 10/09
13
SP4. AIR CLEANER
1. Inspect air cleaner every 250 hours. In dusty condi-
tions, check more often.
2. Marine sets: if dirty, wash element in soapy water.
Rinse and dry thoroughly before re-installing.
Replace if necessary. Part numbers are:
M843N
W2
– #24-22009
3.
NOTE: Make absolutely sure no impurities enter
the engine while changing the element. Do NOT
run the engine with the air cleaner removed.
SP5. V-BELTS
1. Check the tension and wear on the V-belt daily.
2. Use your thumb to press on the belt at the midpoint
between the crankshaft and alternator pulleys. The
tension is correct if the belt can be depressed about
3/16 in. (5 mm).
Servicing
Figure 7: Valve Adjustment
SP6. VALVE CLEARANCES
1. Adjust valve clearance after 1000 hours or as needed.
2. Valve adjustments should be done after the cylinder
head bolts have been re-tightened. Engine should be
cold and NOT running.
3. Watch the valves while turning the engine over by
hand. Turn until the inlet valve starts to open and the
exhaust valve starts to close (the valves are rocking).
Then turn the crankshaft one more full turn and adjust
the clearance on both valves for this cylinder.
Align the top mark of the crank pulley with the top
mark of the timing gear case.
4. Loosen the lock nut and adjust the clearance between
the rocker arm and valve guide of both the intake and
exhaust valves with the adjustment screw (
Figure 7
).
Clearance on both intake and exhaust valves should
be 0.008 in. (0.2 mm).
5. Repeat steps 3 and 4 for each cylinder. Each set of
valves must be adjusted individually.
6. Replace the rocker arm cover. Tighten cover nuts to
5 - 8 ft/lbs (0.8 - 2.3 kg/m).
