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Maintenance: Engine
Engine
Valve clearance
Check and adjust the valve clearance on a cold engine. The valves are adjusted when the piston is at top dead
center of compression stroke. The valve bridge is adjusted first, and then the clearance of the rocker arm.
IMPORTANT!
The engine must under no circumstances be running when checking and adjusting the
valve clearance since the valves can knock against the pistons and cause serious damage.
IMPORTANT!
Make sure that the stop lever is pulled out and the starter key switched off.
Top dead center on compression stroke
1. Turn the engine in the normal direction to align the
timing mark [1 .6] on the damper with the pointer
as shown.
2. Remove the rocker cover of the cylinder on which
the valve clearance is to be checked and adjus-
ted, and make sure the inlet and exhaust valves
have some clearance. If the timing mark [1 .6] is
aligned with the pointer, either the No. 1 or No. 6
piston is at top dead center on the compression
stroke.
Adjust the valve bridge
IMPORTANT!
Make sure the clearance between
the valve bridge and valve rotator is 1.5 mm
[0.059 in.] or more if not, interference will occur
between the bridge and rotator to cause the
valve cones to get out of place. If the clearance
is less than 1.5 mm [0.059 in.] after the height of
valves has been adjusted, consult your dealer.
NOTE!
Before inspecting the valve clearance, adjust
the height of the two valves. Bring the bridge into con-
tact with the valves, by means of the valve-bridge ad-
justing screw, so that there is no difference in height
between the two valves. If the valve seats are worn,
one valve will differ from another in height, increasing
the clearance between the valve stem and bridge,
leading to an increased valve clearance.
1. Unscrew the lock nut and adjusting screw on the
pair of valves on the cylinder so that there is clea-
rance between the yoke and the valve stem.
2. Press the valve yoke down.Turn the adjusting
screw so that it makes contact with the valve
stem.
3. Turn an additional 10 degrees. Lock the adjusting
screw with the lock nut.
NOTE!
Check if the bridge is properly adjusted, by
putting a little drop of oil the valve stem top.
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