SERVICE MANUAL
VALVE TRAIN - CAMSHAFT, TAPPETS & PUSH RODS
Section 4
GENERAL
With the crankcase front cover removed the gear train
becomes visible. The camshaft gear (1, Fig. 2) has
twice as many teeth as the crankshaft gear (2), as
shown.
Figure 2. - Gear Train
1.
Camshaft Gear
2.
Crankshaft Gear
3.
Idler Gear
Therefore, the camshaft rotates at one-half of the
crankshaft speed due to the requirement to open and
close the valves to each cylinder once for every two
revolutions of the crankshaft.
The camshaft bearings are pressure-lubricated and have
holes drilled in them. When the bushings (2, Fig. 3) are
installed, the oil holes must align with the ones drilled in
the crankcase (1). The oil hole in the rear bearing
permits lubricating oil to travel to the valve lever
mechanism.
Figure 3. - Camshaft Lubrication
1.
Drilled Oil Hole in the Crankcase
2.
Bushings
CGES-185-3
PRINTED IN UNITED STATES OF AMERICA
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