Table 4-2. Troubleshooting-Continued

TM 10-3930-632-12

Table 4-2. Troubleshooting-Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

ENGINE-Continued

12. ENGINE LACKS POWER-Continued

Step 6. Check air cleaner element.

Clean or replace element.

Step 7. Check spark plug gaps.

Reset plug gaps.

Step 8. Check to insure that choke and throttle open fully.

Adjust choke, accelerator pedal and governor linkage (para 4-50).

Step 9. Inspect exhaust system for obstructions.

Remove obstructions or replace parts.

Step 10. Check engine compression.

Report condition to general support maintenance personnel.

Step 11. Check valve adjustment.

Adjust valves (para 4-66).

Step 12. Check to insure that sufficient fuel is being supplied.

Clean filter, inspect fuel pump, inspect carburetor for water or dirt and replace as necessary.

13. HIGH ENGINE OIL CONSUMPTION.

Step 1. Check engine speeds with tachometer.

Adjust governor as required.

Step 2. Check for oil leaks.

Report condition to general support maintenance personnel.

Step 3. Check for diluted or improper oil.

Drain and fill with proper grade of oil.

Step 4. Check engine temperatures causing thinning of oil.

Refer to ENGINE OVERHEATS, Item 21, below.

14. LOW ENGINE OIL PRESSURE.

Step 1. Check oil level.

Fill crankcase to full mark to dipstick.

Step 2. Check for improper grade of oil and observe for foaming oil at high engine speeds.

Change oil, inspect crankcase vent tube and check for water in oil.

Step 3. Check for oil leaks.

Report condition to general support maintenance personnel.

15. HIGH FUEL CONSUMPTION.

Step 1. Check carburetor adjustment.

Adjust carburetor as necessary (para 4-42).

Step 2. Check engine speeds.

Adjust carburetor (pare 4-42).

Step 3. Check condition of air cleaner element.

Clean or replace air cleaner element.

Step 4. Check carburetor float level. Test accelerator pump adjustment.

Replace carburetor.

Step 5. Check for fuel line leaks.

Replace lines. Correct leaks.

Step 6. Check engine for overheated condition.

Refer to ENGINE OVERHEATS, Item 21, below.

Step 7. Inspect carburetor for worn and broken parts.

Replace carburetor (para 4-42).

Step 8. Test fuel pump for high pressure and check for leaking diaphragm.

Replace fuel pump (para 4-43).

Step 9. Check ignition timing.

Reset timing.

Step 10. Check filter bowl and gasket for leaks.

Replace defective parts.

Step 11. Check engine compression.

Report condition to general support maintenance personnel.

Step 12. Check to see that choke is fully opening.

Adjust choke control (para 4-42).

Step 13. Test engine idle speed.

Adjust carburetor idle speed screw (para 4-42).

Step 14. Check spark plug condition and gap.

Clean and gap plugs.

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