E. ADJUST SECONDARY THROTTLE STOP
SCREW - Back the secondary throttle stop screw
out until the secondary throttle plates are closed
in the bore. Turn the screw in until it touches the
stop on the lever, then give it one half turn more.
|Figure 33. Secondary Throttle Stop Screw Location|
|F. ADJUSTING THE IDLE - Seat the idle
adjusting needle lightly and back off one full turn.
|Figure 35. Adjusting Idle Air Screw|
|Figure 34. Adjusting Idle Fuel Mixture||Figure 36. Carburetor Adjustments|
|I. ADJUST AIR VENT ROD AND VALVE|
|G. ADJUST IDLE AIR SCREW - The model
4160 with mechanical secondarys has an idle air
adjusting screw located in the main body. Turn this
screw in until it seats lightly and back it off one
full turn. After installation on the engine a reset
ting may be made.
|(1) Adjust air vent rod and valve by
checking the clearance from valve to seat with a
drill with throttles closed. This clearance should
be taken between the valve and the seat and must
be .050 to .070.
|H. ADJUST IDLE SPEED SCREW - On all
models except 4160 with mechanical secondarys,
the idle speed screw must be tightened until the
primary throttle plates are cracked slightly.
|(2) Early production low inlet fuel bowl
models have a different vent rod. The clearance
of the air vent valve on these models is corrected
by bending the end of the pump operating lever.