Pilot Screw Adjustment (U .S.a. Only) 5-1 - Honda Nighthawk CB 750 1991 Service Manual

Fuel System
Pilot Screw Adjustment (U .S. A.
Only)
ldle Drop Procedure
-
If the engine must be running to do some work,
make sure the area is well ventilated. Never run the
engine i n an enclosed area. The exhaust contains
poisonous carbon monoxide gas that may cause loss
of consciousness and lead to death.
NOTE
I
.
Make sure the carburetor synchronization is within
I
specification before pilot screw adjustment.
-
The pilot screws are factory pre-set and no adjustment
is necessary unless the pilot screws are replaced.
Use a tachometer with graduations of 50 rpm change.
1. Turn each pilot screw clockwise until it seats lightly, then
back
it
out to the specification given. This is an initial
setting prior to the final pilot screw adjustment.
Pilot screw wrench 07908-4730001 or
equivalent commercially
available i n U.S.A.
(Cal Van 466)
Initial Opening: 2-518 turns out (49 states model)
:
2-318 turns out (California modell
CAUTION
-
Damage t o the pilot screw seat will occur if the pilot
screw is tightened against the seat.
2. Warm up the engine to operating temperature.
Stop and go riding for 10 minutes is sufficient.
3. Attach a tachometer according to its manufacturer's
instructions.
4. Adjust the idle speed to the specified rpm with the throttle
stop screw.
ldle Speed: 1,000+ 100 rpm
5. Turn all oilot screws 1 12 turn counterclockwise from the
intial setting
Pilot screw wrench 07908-4730001 or
equivalent commercially
available i n U.S.A.
(Cal Van 466)
6. If the engine speed increases by 50 rpm or more, turn all
pilot screws out by successive 112 turn increments until
engine speed does not increase.
7. Adjust the idle speed with the throttle stop screw.
8. Turn the No.2 carburetor pilot screw in until the engine
speed drops 50 rpm.
9. Then turn the No.2 carburetor pilot screw counterclock-
wise 1/2 turn from the ~osition obtained in steo 8.
.
10. Adjust the idle speed with the throttle stop screw.
11. Perform steps 8.9 and 10 for the No. 1.3 and
4
carbu-
retor pilot screws.
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