Fuel Strainer, Fuel Lines, and Fittings

TM 5-4320-234-12

c. The fuel strainer (16) contains a filter for

thermostatically controlled heat valve to direct exhaust

gases through passages in the intake manifold to

removing dirt from the fuel.

It is encased in a

provide faster engine warmup.

removable glass bowl which permits quick visual

inspection of the fuel for the presence of water or dirt.

g. The emission control system recirculates

Another fuel line connects the fuel strainer to the fuel

combustion gases which blow past the pistons, so that

inlet of the carburetor.

these gases are burned in the engine. The flow is

d. The carburetor (12) is a single-barrel, updraft

controlled by an emission control valve which diverts the

gases from the crankcase through a tube and into the

design which is secured to the intake manifold. It

intake manifold. Crankcase pressure is regulated by a

contains its own filter mounted near the fuel inlet. The

pressure control chamber which is part of the emission

carburetor fuel bowl has a drain plug to permit removal

control valve. The emission control system helps to

of contaminated fuel, and a drain cock to remove

prevent engine blow-by gases from polluting the

excess fuel if the engine becomes flooded.

atmosphere.

e. The governor (9, fig. 4-7) operates the throttle

4-21. Fuel Strainer, Fuel Lines, and Fittings

control of the carburetor (12) to provide the required

engine speed, depending upon the setting of the manual

a. Fuel Strainer Service. If moisture or other

throttle control. The engine will maintain the set speed

regardless of load, provided the load applied does not

contaminants are visible through the glass bowl of the

exceed the horsepower rating of the engine. Several

fuel strainer, service the fuel strainer as directed in

adjustment points are provided to ensure proper engine

paragraph 3-11.

governor control.

b. Removal. Remove the fuel strainer and the fuel

f. The intake manifold (18) and exhaust manifold

lines and fittings as shown in items 1 through 10 of

(4) are bolted directly to the cylinder head and are

figure 4-8 and items 1 through 10 to figure 4-9.

sealed with a gasket. The intake manifold provides

mounting for the carburetor and directs the fuel and air

mixture to the cylinders. The exhaust manifold routes

the exhaust gases through the muffler. It includes a

4-17