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Plain Washer (2)
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~~
L
,:IJ..
Fillister Head Sems
Screws (2)
~
\Fuel Pump
Mounting Flange
Figure 6-3. Installing Fuel Pump.
NOTE: Make sure that the fuel pump lever is posi-
tioned above the camshaft. Damage to the fuel
pump and severe damage to the engine could re-
sult if the lever is positioned below the camshaft.
Make sure that the flat washers are installed next
to the mounting flange to prevent damage from
the lock washers.
If a metal bodied pump was replaced by a plastic
bodied pump, make sure that the old thick gasket
is discarded and the new thin gasket is used.
3.
Torque screws to
37 - 45
in.llb.
4.
Connect fuel lines to inlet and outlet fittings.
CARBURETOR - GASOLINE
£
WARNING: Explosive Fuel!
Gasoline may be present in the carburetor and fuel
system. Gasoline is extremely flammable and
it
can
explode if ignited. Keep sparks, open flames, and
other sources of ignition away from the engine. Dis-
connect and ground the spark plug lead to prevent
the possibility of sparks from the ignition system.
Adjustment
The carburetor is designed to deliver the correct
fuel/air mixture to the engine under all operating
conditions. Carburetors are set at the factory and
normally do not need adjustment. If the engine
exhibits conditions like those found in the table
that follows, it may be necessary to adjust the
carburetor.
In general, turning the adjusting needles in (clock-
wise) decreases the supply of fuel to the carbure-
tor. This gives a leaner fuel-to-air mixture. Turning
the adjusting needles out (counterclockwise) in-
creases the supply of fuel to the carburetor. This
gives a richer fuel-to-air mixture. Setting the nee-
dles midway between the lean and rich positions
will usually give the best results. Adjust the carbu-
retor as follows:
1 . With the engine stopped, turn the low idle fuel
adjusting needle in (clockwise) until it bottoms
lightly.
NOTE: The tip of the low idle fuel and high idle fuel
adjusting needles are tapered to critical dimensions.
Damage to the needles and the seats in carburetor
body will result if the needles are forced.
2.
Preliminary Settings: Turn the adjusting needles
out (counterclockwise) from lightly bottomed
according to the table shown in Figure 6-4.
3.
Start the engine and run at half throttle for five
to ten minutes to warm up. The engine must
II
be warm before making final settings (Steps 4,
•
5, 6, and 7).
4.
High Idle Fuel Needle Setting: This adjustment
is required only for adjustable high idle (main)
jet carburetors. If the carburetor is a fixed
main jet type, go to step 5.
Place the throttle into the "fast" position. If possi-
ble, place the engine under load.
Turn the high idle fuel adjusting needle out (coun-
terclockwise) from the preliminary setting until the
engine speed decreases (rich}. Note the position
of the needle.
Now turn the adjusting needle in (clockwise). The
engine speed may increase, then it will decrease
as the needle is turned in (lean). Note the position
of the needle.
Set the adjusting needle midway between the rich
and lean settings. See Figure 6-5.
5.
Low Idle Speed Setting: Place the throttle con-
trol into the "idle" or "slow" position. Set the
low idle speed to 1200 rpm* (
+
or - 75 rpm)
by turning the low idle speed adjusting screw
in or out. Check the speed using a tachome-
ter.
NOTE: The actual low idle speed depends on the
application. Refer to the equipment manufacturer's
instructions for specific low idle speed settings.
The recommended low idle speed for Basic En-
gines is 1200 rpm. To ensure best results when
setting the low idle fuel needle, the low idle speed
must not exceed 1500 rpm.
6.3
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