Section VIII. MAINTENANCE OF AIR CLEANER, EXHAUST SYSTEM, AND ENGINE HOUSING

Section VII. RADIO INTERFERENCE SUPPRESSION

4-16. Replacement of Suppression Components

4-15. General Methods Used To Attain Proper

This equipment uses no primary radio suppression

Suppression

components. Replace the secondary radio suppression

Essentially, suppression is attained by providing a

components as follows:

low resistance path to ground for stray currents. The

methods used include shielding the ignition and high

a. Replace the shielded spark plug cables as

frequency wires and grounding the frame with bonding

directed in paragraph 4-33.

straps.

b. Replace the magneto ground strap as directed

in paragraph 4-34.

Section VIII. MAINTENANCE OF AIR CLEANER, EXHAUST SYSTEM, AND ENGINE HOUSING

4-17. Description

a. Service.

(1) Stop the engine (para 2-9).

a. Air Cleaner. The air cleaner (fig. 1-1) is

(2) Loosen the wing bolt on the clamp

mounted on the end of the engine housing opposite the

assembly (1, fig. 4-4) and remove the assembled dust

radiator. It is a dry-type unit which uses a porous paper

cup (3) and flexible baffle (2). Remove the baffle from

element to screen the particles of dust and dirt from the

the dust cup and empty the dust from the dust cup.

air before the air enters the carburetor. A flexible hose

(3) Remove the wing nut (4) with its

connects the air cleaner and carburetor.

Proper

assembled washer 'gasket (5) and remove the element

maintenance requires cleaning or replacement of the air

(6) from the air cleaner body(7).

cleaner element when the restriction indicator shows a

Caution

restricted condition. This occurs when the engine is

Do not use gasoline or other

running and the clogged condition of the air cleaner

solvents for cleaning the air cleaner

prevents sufficient air from entering the engine. The

element.

partial vacuum in the air lines trips the restriction

(4) To clean the air cleaner element, use a

indicator, indicating the need for servicing or

1/8-inch air nozzle with 100 psi maximum compressed

replacement of the air cleaner element.

air, blowing from the inside toward the outside until all

dust is removed.

b. Muffler. The muffler (fig. 1-1) is a hollow

Caution

cylinder containing internal baffles which break up the

Mechanical drying methods can be

flow pattern of the exhaust gases expelled by the engine

used providing that the heated air

to provide quiet engine operation. It is mounted on the

does not exceed a temperature of

top of the engine to provide quiet engine operation. It is

180 with the air under constant

mounted on the top of the engine housing and is

circulation. Do not attempt to use

connected to the exhaust manifold of the engine by a

light bulbs for element drying.

pipe nipple. A heat shield is mounted between the

(5) An alternate method of cleaning the

muffler and housing to minimize heat transfer to the

element is to wash it with a nonsudsing detergent in a

housing.

container large enough to immerse the element. Allow it

to soak for 10 minutes minimum and agitate it for 2

c. Engine Housing. The engine housing protects

minutes to dislodge all dirt. Rinse with clean water,

the engine from the weather, aids cooling by directing

using a pressure hose from a tap with pressure of less

the air flow around the engine, and provides a mounting

than 40 psi. Air dry thoroughly before reinstallation.

for the air cleaner and muffler.

(6) Insert a light bulb in the cleaned element

and carefully check for holes, cracks, or ruptures. A

4-18. Air Cleaner and Piping

hole in the element will necessitate element

replacement. Any hole, no matter how small, will cause

Note

unnecessary engine wear.

The air cleaner element must be

(7) Install the element in the air cleaner body

replaced after one year of service or

(7). Check that the washer gasket (5) on the wing nut is

after it has been cleaned six times,

in good condition; secure the element to the body with

whichever comes first.

the wing nut.

4-7