TM 5-4240-501-148P
CARBURETION
Vacu-Jet and One Piece Flo-Jet
Fig. 69 - Adjust Choke Link
Install Carburetor
Install carburetor and fuel tank as an assembly. Hook
throttle link into carburetor throttle and governor lever.
(For various hook-ups, see Remote Control, Section 4.)
Raise carburetor into place, insert a new gasket and
fasten with mounting screws.
Install governor spring. Install ground wire and remote
control where used. Fig. 70.
Fig. 70 - Install Carburetor
Choke-A-Matic Remote Controls
See Remote Controls, Section 4, for illustrations by
engine model.
Carburetor Adjustment
The initial setting of the needle valve, Fig. 71, is made by
turning the needle valve all the way in, then turning out
11/2 turns. Final adjustment is made with the engine
running.
Fig. 71 - Carburetor Adjustment
NOTE: All carburetor adjustments should be made with
the air cleaner on engine. Best adjustments made with
fuel tank 1/2 full.
FINAL ADJUSTMENT
Place governor speed control lever in "FAST" position.
Turn needle valve slowly in until engine misses
(clockwise - lean mixture) then turn it out slowly past
smooth operating point until engine runs unevenly (rich
mixture). Now turn needle valve to the midpoint between
rich and lean so the engine runs smoothly. Next, adjust
idle RPM. Rotate throttle counterclockwise and hold
against stop. Adjust idle speed adjusting screw to obtain
1750 RPM minimum. Release throttle - engine should
accelerate without hesitation or sputtering. If engine
does not accelerate properly, the carburetor should be
readjusted, usually to a slightly richer mixture.
ONE PIECE FLO-JET CARBURETOR
Fig. 72 - Small One Piece Flo-Jet Carburetor
Fig. 73 - Small One Piece Flo-Jet Carburetor
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