Intake and Exhaust Manifolds

TM 5-4320-234-12

b. Cleaning and Inspection.

(4) With the manifold off the engine, separate

items 9 and 15 by removing nuts (11) and washers (12).

WARNING

(5) Remove gaskets (10 and 14) and studs

Clean all parts in a well-ventilated area.

(13).

Avoid inhalation of solvent fumes and

b. Cleaning and Inspection.

prolonged exposure of skin to cleaning

(1) Clean the exteriors of the manifolds with a

solvent. Wash exposed skin thoroughly.

wire brush. Check that the intake, exhaust, heat control,

Dry cleaning solvent (fed. spec. P-D-680)

and emission control passages are clear.

used to clean parts is potentially dangerous

(2) Inspect the manifolds for cracks, severe

to personnel and property. Do not use near

corrosion, or other damage. Replace as necessary.

open flame or excessive heat. Flash point of

(3) Check operation of heat control valve and

solvent is 100 o to 138 F (38 to 59 C).

free it if stuck. Lubricate shaft with colloidal graphite

(MIL-G-17745A). If thermostatic spring, valve, or shaft

(1) Wipe the exterior of the emission control

is damaged, replace the exhaust manifold.

valve with a cloth dampened with dry cleaning solvent

(4) Check for loose or damaged studs. Replace

(fed. spec. P-D-680). Do not soak the valve in solvent.

if necessary.

(2) Clean the remaining parts with solvent; dry

(5) Remove old gaskets. Use a gasket scraper

thoroughly.

or knife to remove all traces of old gaskets from mating

(3 Inspect the hose for cracks, clogging, and

surfaces.

deterioration; replace a defective hose.

(4) Inspect the emission control valve for

Installation.

cracks, dents, distortion, and other damage.

(1) Assemble intake manifold to exhaust

Make sure the inside element is free. Replace if

manifold and tighten nuts to 25 to 30 foot-pounds.

defective.

Locate gasket (10, fig. 4-11) over studs on cylinder

head and install manifolds (9 and 15). Torque nuts (6)to

c. Installation. Installation of the emission control

25 to 30 foot-pounds.

parts is the reverse of removal. Refer to items 1

(2) Install crankcase emission tube (2) on elbow

through 4 of figure 4-11.

(3).

(3) Install muffler and piping (para 4-18).

4-26. Intake and Exhaust Manifolds

(4) Install carburetor (para 4-24).

4-27. Engine Speed Governor Adjustment

a. Removal.

(1) Remove carburetor (para 4-24).

Adjust the engine speed governor as follows:

(2) Remove muffler and piping (para 4-18).

(3) Remove crankcase emission tube (2, fig. 4-

a. Start the engine and allow it to warm to

11) from elbow (3). Remove 11 nuts (6) and washers

operating temperature. While it is warming up, back out

(7) from studs (8) in cylinder head. Remove manifolds.

the surge adjusting screw (7, fig. 4-12) so that it will not

If they are stuck, you can loosen them by rapping lightly

influence the governor setting.

on them with a soft-faced hammer.

4-24