Honda ST50 1969 Shop Manual page 92

PILOT SCREW ADJUSTMENT
NOTE
CT70 '79 ADDENDUM
The pilot screw is factory pre-set. Adjustment is not
necessary unless the carburetor is overhauled or a
high altitude main jet is installed.
Turn the pilot screw clockwise until it seats lightly
back it out l-3{4 turns. This is a preliminary set-
ting prior to the fina l Pi.lot Screw Adjustment.
CAUTION
Damage to the .pilot screw seal will occur if the pilot
screw is tightened against the seat.
2. Warm up the engine to operating temperature. Stop
and go driving for ten minutes is sufficient.
3.
Attach a tachometer.
4. Adjust the idle speed with the throttle stop screw.
IDLE
SPEED: l ,300
:!:
I 00 rpm
5. Screw the pilot screw in gradually until the engine
stops.
6. Turn !he pilot screw
3{4
of a turn out from this
position.
7. Restart the engine and readjust the idle speed with
the throttle stop screw if necessary. ·
HJCH ALTITUDE ADJUSTMENT
The carburetor must be adjusted for high altitude riding
(2,000 M, 6,500 ft).
STANDARD SETIINC : 2,000m (6,500 ft) max.
HIGH ALTITUDE SETTING: l,500m (5,000
ft) min.
Carburetor adjustment is as follows:
I . Remove thecarburelor
2. Remove the float bowl.
3.
Replace the main jet with the high altitude type.
4. Assemble and install thecaburetor.
5. Screw in the pilot screw 1/8 of a tum.
6. Start the engine and adjust the idle speed wi1h the
th rottle stop screw.
NOTE
Readjust the pilot
screw if the engine idle1 rough,
misses, or stalls, acco rding to the instructions on
page 21.
CAUTION
Sustained operation at altitudes lower than 1,500
meters (5,000 ft) with the high altitudes specifica-
tions may cause engine overheating and damage.
Reinstall the standard main jet and tum the pilot
screw I /8 turn out when operating the vehicle below
1,500 meters(S,000 ft).
91