Check valve clearance with cold engine by means of a 0.20 mm (0.008 in) feeler gauge (7). To do this,
turn crankshaft until the piston reaches the compression dead center, i. e. after overlapping of both
valves (exhaust valve about to close, inlet valve about to open) go on turning the crank-shaft through
3600C, corresponding to a complete rotation.
The resulting gap (1) between rocker arm (3) and valve (5) should now admit with a slight drag the 0.20
mm feeler gauge (7) at the inlet and exhaust valves. If the gap is found to be too small or too big,
slacken lock nut (2) by giving it one or two turns and adjust screw (4) with a flatnose plier so that, when
lock nut (2) has been retightened, the feeler gauge (7) can be withdrawn easily.
Replacing fuel filter.
Screw off filter carefully as fuel from higher level will run out.
Before refitting the new filter, wet the rubber seal with a drop of oil. Then screw in filter by hand until the
seal is squarely seated and tighten filter by a further half turn.
After mounting, check for leaks during a short test run.
Intake and exhaust manifolds. After every 600 running hours check the intake and exhaust manifolds for
tightness at the cylinder heads, retighten fastening bolts if necessary.
Tiqhteninq cylinder head nuts. After removal of the cylinder head cover, cylinder head nuts and nuts of the
rocker arm bracket are accessible. Retighten cylinder head nuts crosswise with cold engine, i. e. 1, 2, 3, 4 (refer to figure
Figure 4-11. Cylinder Head Tightening Sequence.