Section 04
FUEL SYSTEM
Subsection 03
(CARBURETOR)
04-03-4
VMR2004_137_04_03A.FM
Align carburetor notch with the flange recess.
TYPICAL
Carburetor notch aligned with the flange recess
Install air filter box.
Carburetor Adjustments
BOTTOM VIEW
1. Idle speed screw
2. Pilot screw
3. Drain plug and screw
Idle Speed Preliminary Adjustment
Adjust throttle screw to 1-1/2 turn or so that throt-
tle valve closes bypass hole by half, as shown in
the next photo.
1. Bypass hole closes to halfway
Idle Speed Adjustment
Start engine and allow it to warm then adjust idle
speed to specifications by turning
idle speed
screw
clockwise to increase engine speed or
counterclockwise to decrease it.
NOTE:
Use the digital induction tachometer
(P/N 529 014 500). Turn tachometer wire around
spark plug wire, about 4 or 5 turns, for the best
measure.
CAUTION:
Do not attempt to set the idle speed
by using the pilot screw.
Refer to TECHNICAL DATA for idle speed specifi-
cations.
Pilot Screw Adjustment
NOTE:
The pilot screw is factory pre-set. Warm
the engine to operating temperature.
Turn the pilot screw clockwise until you hear the
engine missing or decreasing idle speed, then turn
counterclockwise until the engine again misses or
decreases idle speed.
Center the pilot screw exactly between these two
extreme positions then unscrew the pilot screw
of 3/8 turn.
If idle speed changes after adjustment of the pilot
screw, readjust the idle speed screw.
V07F07A
3
1
V07F08A
2
1
V04F0LA