Section IX. FUEL SYSTEM

and ignition.

(7) A vacuum pressure that is normal, but which

(4) If vacuum indicated is a steady 8 to 12 inches

drops at regular intervals, indicates defective valves

it indicates worn valve guides, worn piston rings,

or a leaking cylinder head gasket.

poor lubricant, or a leak in the intake manifold.

(8) Install timing cover on flywheel housing.

(5) A vacuum below five inches indicates a leak

(9) Remove vacuum gage from manifold and refer

in the intake manifold.

to paragraph 3-26 and connect vent valve and hose to

(6) A vacuum pressure that is normal, but which

intake manifold.

drops at irregular intervals, indicates sticking valves,

incorrect carburetor fuel mixture, or defective spark

plugs.

Section IX. FUEL SYSTEM

3-28. General

flange of the intake manifold. A cable from the choke

lever is connected to a choke bracket on the carbure-

The engine fuel system consists of a fuel tank, mech-

tor throat. Linkage from the accelerator connects

anical fuel pump with filter, a single-vented updraft

to the throttle lever. The governor linkage connects

carburetor, a centrifugal governor, and connecting

to the throttle lever shaft.

fuel lines. An electrical transmitter, located in the

b. Removed. Refer to figure 3-13 and remove the

fuel tank, operates a fuel level indicator (fig. 2-2)

carburetor as follows:

to show fuel in the system.

(1) Disconnect fuel line from carburetor inlet.

3-29. Carburetor

a. General. The carburetor is mounted on the lower

Figure 3-13. Carburetor, installed view.

3-17