TM 5-4240-501-148P
CARBURETION
Pulsa-Jet
Choke-A-Matic Remote Controls
See Section 4 for illustrations by engine model.
Install Carburetor
Except Model 100900 and 130900
Install carburetor and tank as one assembly on engine.
Hook throttle link into carburetor throttle and governor
lever (for various illustrations, see Section 4). Raise
carburetor into place, insert a new gasket and fasten with
mounting screws. Install governor spring. Fig. 56. Install
ground wire and remote control where used.
Fig. 56 - Installing Ground Wire
Install Carburetor Model 100900, 130900, and 131900
Assemble carburetor to tank. Hold throttle link to throttle.
Fig. 57. Slip carburetor over notch in cylinder shield and
around intake tube. Oil the seal in carburetor body to
prevent damage, when installing. Mount tank to cylinder.
Hook up ground wire and governor spring.
Fig. 57 - Install Carburetor - Model 100900 and
130900
Fig. 57A - Install Carburetor - Model 131900
Carburetor Adjustment
Turn needle valve clockwise until it just closes.
CAUTION: Valve may be damaged by turning it in too
far.
Now open needle valve 11/2 turns counterclockwise, Fig.
58. This initial adjustment will permit the engine to be
started and warmed up prior to final adjustment.
NOTE: All carburetor adjustments must 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 in until engine misses (clockwise -
lean mixture) then turn it out 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. Release
throttle - engine should accelerate without hesitation or
sputtering. If engine does not accelerate properly, the
carburetor should be re-adjusted, usually to a slightly
richer mixture.
Fig. 58 - Setting Needle Valve
NOTE: When starting a Pulsa-Jet engine for the first
time, fill fuel tank completely full. This eliminates priming
the fuel pump. thus insuring a quick start.
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