TM 5-4240-501-148P
CARBURETION
Pulsa-Jet, Vacu-Jet (Vertical Crankshaft)
4.
To check adjustment move engine control from
SLOW to FAST speed. Engine should accelerate
smoothly. If engine tends to stall or die out, increase
idle speed or re-adjust carburetor, usually to a
slightly richer mixture.
NOTE: Flooding can occur if the engine is tipped at
an angle for a prolonged period of time, if the engine
is cranked repeatedly when the spark plug wire is
disconnected or if carburetor mixture is adjusted too
rich.
In case of flooding, move the governor control to the
"Stop" position and pull the starter rope at least six
times. (Crank electric starter models for at least 5
seconds.)
When the control is placed in the "Stop" position the
governor spring holds the throttle in a closed (idle)
position. Cranking the engine with a closed throttle
creates a higher vacuum which opens the choke
rapidly, permitting the engine to clear itself of excess
fuel.
Then move the control to "Fast" position and start
engine. If engine continues to flood, lean carburetor
needle valve -1/8 to 1/4 turn clockwise or see page
5.
If the engine on a mower with a high-inertia disc type
cutter blade becomes hard starting when the engine is
warm, a leaner carburetor mixture may be required.
A heavy, high-inertia disc type cutter blade rotates for a
longer period of time, after the governor control is placed
in the STOP position. During this "coasting" period, the
engine continues to induct the fuel-air mixture, even
when the choke is open. If the carburetor mixture is too
rich, the warm engine may flood and become hard
starting. If the original carburetor adjustment has not
been changed, turn the needle valve clockwise (leaner)
approximately 1/8 turn. If the original carburetor
adjustment
has
been
changed,
follow
previous
adjustment procedure paragraph No. 2 A, B and C, then
adjust 1/8 turn leaner.
Cleaning Fuel System
Gummy or dirty fuel tanks, lines and carburetors should
be cleaned in a carburetor cleaner, such as Bendix. Do
not soak diaphragms or nylon parts in cleaner.
MODEL SERIES 82000, 92000, 94000, 110900 and
111900 only
Model Series 82500, 92500 and 94500 have a VacuJet
carburetor. Model Series 82900, 92900, 94900, 110900
and 111900 have a Pulsa-Jet carburetor.
Remove carburetor and fuel tank assembly mounting
bolts, Fig. 18.
Fig. 18 - Removing Mounting Bolts
Slip carburetor and fuel tank assembly off end of fuel
intake tube and turn assembly to free throttle link from
throttle lever. This will leave governor link and governor
spring connected to the governor blade and control lever,
Fig. 19.
Fig. 19 - Remove Carburetor and Tank Assembly
MODEL SERIES 94000
Disconnect governor spring from control lever. Slide
carburetor and fuel tank assembly off end of fuel intake
tube and turn assembly to disconnect governor link from
bell crank lever. This will leave governor spring and bell
crank assembly on carburetor and fuel tank assembly,
Fig. 20.
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