TM 5-4240-501-14&P
CARBURETION
Two Piece Flo-Jet
Fig. 85 - Typical Two Piece Flo-Jet Carburetor
Check Upper Carburetor Body for Warpage
With carburetor assembled and body gasket in place, if a
.002" feeler gauge can be inserted between the upper
and lower bodies at the air vent boss, just below the idle
valve, the upper body is warped or gasket surfaces are
damaged and should be replaced. Fig. 86.
Fig. 86 - Checking Carburetor Body
Check Throttle Shaft and Bushings for Wear
Wear between throttle shaft and bushings should not
exceed .010". Check wear by placing a short iron bar on
the upper carburetor body as shown in Fig. 87. Measure
the distance between the bar and shaft with a feeler
gauge while holding the shaft down and then holding
shaft up. If the difference is over .010", either the upper
body should be rebushed, the throttle shaft replaced, or
both. Wear on the throttle shaft can be checked by
comparing the worn and unworn portions of the shaft.
To replace bushings, see "Remove Throttle Shaft and
Bushings."
Fig. 87 - Checking Throttle Wear
Remove idle valve. On small line Flo-Jet loosen high
speed valve packing nut. Remove packing nut and
needle valve together. On medium and large line Flo-Jet
remove high speed valve assembly. Remove nozzle on
small line Flo-Jet with 19061 screw driver. On medium
and large line Flo-Jet use 19062 screw driver to remove
nozzle. Using 19061 or 19062 will help to prevent
damage to the threads in lower carburetor body. The
nozzle projects diagonally into a recess in the upper body
and must be removed before the upper body can be
separated from the lower body, or the nozzle will be
damaged. See Fig. 85. Remove screws holding upper
and lower bodies together. A pin holds the float in place.
Remove pin and remove float and float needle as an
assembly. Use wide blade screw driver that fits slot to
remove float inlet seat. On carburetors with pressed in
float seats, see "Replacing Pressed In Float Valve Seat."
On small Flo-Jets the venturi is a separate part and can
be slipped out of the lower body. Some carburetors have
a welch plug. This should be removed, only if it is
necessary, to remove the choke shaft or choke plate.
Some carburetors have a nylon choke shaft. Remove as
shown in Fig. 88.
Fig. 88 - Nylon Choke Shaft
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