75. Replacing Fuel Pump
a. Removal (fig. 20).
(1) Disconnect the inlet and outlet fuel lines from the tube elbows in the fuel pump cover.
(2) Remove the mounting bolts and lockwashers that attach the fuel pump to the engine crankcase, and
carefully lift off the fuel pump and pump mounting gasket.
b. Installation (fig. 20).
(1) With the mounting gasket in place against the mounting surface of the pump body, insert the rocker arm on
the fuel pump through the opening in the engine. Make sure that the "pad" or flat surface of the rocker arm
rests against the fuel cam of the engine camshaft.
(2) Hold the pump and gasket in position against the engine and install the two mounting bolts and
lockwashers. Start the bolts by hand to prevent damage to the threads; then tighten them securely with a
wrench.
(3) Make certain that the fuel lines are in proper alinement with the tube elbows in the pump cover. Connect
both fuel lines, starting the tube nuts with the fingers and then tightening securely with a wrench of proper
size.
76. Servicing Engine Air Cleaners
a. The air filter covers (4) are held in place with a spring (3).
Remove the covers and lift out the filter elements (6).
b. Blow out the filter elements with compressed air. Wipe out the inside of the filter connections with a lint-free cloth
dampened with solvent.
c. If, upon inspection, gaskets have loosened from the air cleaner, remount and adhere with Pliobond or No. EC 11
cement.
d. After cleaning, insert the filter elements down into the connections, and reinstall the covers.
77. Carburetor Description and Adjustment
a. Description (fig. 22). The carburetor is a single downdraft unit, incorporating both a primary and secondary
venturi. A fuel screen in the fuel inlet can be removed for cleaning or replacement by unscrewing the hex head plug that
holds the screen in place. Fuel enters the bowl by passing around the fuel valve. The fuel valve assumes a more or less
fixed opening, as regulated by the float, sufficient to maintain a proper level in the fuel bowl equal to the fuel demand of the
engine. At slow idle, the idle adjusting needle controls the idle mixture delivery. Turning the
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