TM 5-4520-241-14
Table 4-2. Organizational Maintenance Troubleshooting - Continued
MALFUNCTION
TESTING OR INSPECTION
CORRECTIVE ACTION
8 - Continued
Tighten clamps at burner head and combustion air motor outlet. If duct is punctured or torn,
loosen clamps and remove damaged air duct. Install new duct and secure with clamps.
Step 3.
Check wiring to combustion motor. Inspect wiring from terminal strip to motor.
Tighten loose connections, or replace broken wires.
Step 4.
Check for fuel in float bowl. Remove pipe plug (1, fig. 4-11) from side of float bowl. Using small
wire or pencil tip, gently tap float. It must bounce up and down to show that fuel is present in bowl.
If float bounces, proceed to step 5. If float does not bounce, inspect screen and needle.
Disconnect fuel line from elbow (2, fig. 4-11). Unscrew elbow and pull out screen (3). Clean or
replace screen. If it is clean, inspect needle and seat. Remove screws (5) and washers (6). Pull
off cover (7) and gasket (8). Remove pin (9) and pull off float (10) and needle (11). If needle or
seat (12) is damaged, replace needle, seat, and washer (13) as an assembly. Reassemble in
reverse order of removal.
Step 5.
Check for fuel suction. Disconnect solenoid power lead at electrical connector. Use a pencil to
mark the position of the fuel needle in the carburetor body. Carefully unscrew and remove fuel
needle (1, fig. 4-12) counting the number of turns until needle is free. Connect power plug. Turn on
heater and feel for vacuum at the fuel needle hole in the carburetor body. You should feel a
vacuum if you place your finger over the hole. If there is a vacuum, check per step 6. If there is no
vacuum, clean fuel jet and mixer.
Do not reinstall fuel needle.
Disconnect fuel lines and wires from carburetor. Remove screws (3, fig. 4-12) and washers (4)
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