Onan CCK Service Manual

VALVE
INTAKE AND EXHAUST VALVES
(SEE TABLE OF CLEARANCES) ,
✓
FIGURE 6S, VALVE FACE AND SEAT ANGLES
marks at intervals across the valve face and observe if
the marks rub off uniformly when the valve is rotated
part of a turn against the seat
Lightly oil the valve stems and reassemble all parts
removed. Adjust the valve clearance (see Tappet
Adjustment ),
The positive type valve rotocoils serve to prolong
valve life and decrease valve repairs. Check the
rotocoils periodically by removing the cylinder heads
and cranking the engine. When functioning properly,
the valve is rotated a fraction of a turn each time it
opens. If rotocoils are faulty, install new ones.
TAPPET ADJUSTMENT
The engine is equipped with adjustable tappets. To
make a valve adjustment, remove the valve covers.
Crank the engine over slowly by hand until the left
hand intake valve, when facing the flywheel, opens
and closes. Continue about 1/4 turn until the correct
timing marks align. This should place the left hand
piston at the top of its compression stroke, the
position it must be in to get proper valve adjustment
for the left hand cylinder. Clearances are shown in
Dimensions and Clearances section. For each valve, the
gauge should just pass between the valve stem and
valve tappet. Figure 66.
To correct the valve clearance, turn the adjusting
screw as needed to obtain the right clearance. The
screw is self-locking.
To adjust the valves on the right hand cylinder, crank
the engine over one complete revolution and again
line up the correct timing marks. Then follow the
FIGURE €6. ADJUSTING TAPPETS
REMOVING PISTON WITH LARGE WEAR
RIOGE COULD BREAK RING OR RING LAND.
FIGURE 67. WEAR RIDGE ON CYLINDER WALL
adjustment given for the valves of the left hand
cylinder.
PISTONS AND RINGS
Whenever there is a noticeable wear ridge at the top of
each cylinder, remove the ridge with a ridge reamer
before removing the pistons. If not, the rings can
catch the ridge when pushing out the pistons and
cause a ring land fracture. Figure 67.
57

Onan CCK Specifications

General

Cylinders	2
Ignition System	Battery ignition
Fuel Type	Gasoline
Cooling System	Air-cooled
Fuel System	Carburetor
Starter	Electric
Governor	Mechanical
Max RPM	1800 RPM
Engine Type	4-cycle
Bore and Stroke	3.25 x 3.625 inches (82.55 x 92.08 mm)