Valve Adjustment - Honda CB350 Repair Manual

26 TUNE—UP
spark plugs. Using the rotor bolt, turn
the crankshaft counterclockwise while
watching the left cylinder intake tappet;
when the tappet descends all the way
and then starts to rise, line up the "LT"
mark on the rotor with the index mark on
the stator. In this position the left cylin—
der is at top dead center (TDC) of the
compression stroke. Turn the crankshaft
another 90° (counterclockwise). The
valves should all be closed in this posi—
tion. This is the only position that the
cam chain tensioner may be adjusted in.
2. Loosen the setting bolt locknut and
back the setting bolt out a few turns, the
tension will automatically be adjusted.
Tighten the setting bolt and the locknut.
3. If after performing the adjustment
outlined above, the cam chain still is ex—
cessively noisy, perform the adjustment
as described below.
NOTE: When listening for cam chain
noise the valves should be adjusted
properly so that tappet noise will not
be confused with cam chain noise.
4. Start the engine and as soon as the
engine will idle with the choke off, per—
form the adjustment by removing the
plunger cap. Loosen the setting bolt lock—
nut and back out the setting bolt a few
turns. Push the tensioner plunger in with
a screwdriver until the cam chainis silent
and, while maintaining pressure with the
screwdriver, tighten the setting bolt and
locknut. Do not use more pressure on the
plunger than is necessary, as this will
overtighten the chain and cause rapid
wear of the cam chain and the tensioner
components. Install the plunger cap.
Valve Adjustment
NOTE: Valves must be adjusted when
the engine is cold, preferably after sit—
ting overnight.
350 MODELS
1. Remove the alternator cover, intake
and exhaust valve caps, and the point and
tach drive housing covers.
2. Remove the spark plugs.
3. Turn the engine over slowly in the
normal direction of 'rotation (the rotor
will turn counterclockwise) while ob—
Cam chain setting bolt (1), locknut (2), and plunger
cap (3) (360)
Stator
Indexg\
Alternator rotor marks indicating that the left cylin—
der is at top dead center
serving the left intake valve. When the
valve goes down and begins to come up,
continue turning the engine over until
the "LT" mark on the rotor lines up with
the timing index mark on the stator.
4. The left piston should now be at top
dead center (TDC) of the compression
stroke with both valves closed. Check
for clearance at both valves for the left
cylinder. Each should have a slight
amount of free—play. If they do not, the
piston is at TDC on the exhaust stroke.
Turn the rotor 360° and check again.
5. Valve clearance is 0.05 mm (0.002
in.) for the intake valves and 0.1 mm
(0.004 in.) for the exhaust valves. f
6. Slip the correct feeler gauge be—
tween the rocker arm and the valve stem.
The feeler gauge should be a slip fit (a
light drag) in a correctly adjusted valve.
7. If adjustment is necessary, loosen
the locknut on the rocker arm shaft (in the
point and tach drive housings) and turn
the rocker arm shaft until the adjustment
is correct. Tighten the locknut and re—
check the adjustment.