Section III. TROUBLESHOOTING
51. General
This section provides information useful in detecting, diagnosing, and correcting malfunctions in the water
distributor and its components. Opposite each statement of a typical troubleshooting problem is the statement
of possible recommended remedies for solution of the problem. Any operational trouble beyond the scope of
the operator or crew should be reported to organizational maintenance.
52. Engine Fails or Hard To Start
Probable cause
Possible remedy
Lack of fuel
Fill fuel tank.
Fuel shutoff valve closed.
Open the shutoff valve
Engine flooded by too much fuel.
Crank engine with throttle wide open, or let the engine sit
for a few minutes and repeat the starting operation.
53. Engine Misses or Runs Erratically
Probable cause
Possible remedy
Empty fuel tank
Fill fuel tank.
Water in fuel
Drain fuel system and fill with fuel.
Excess of foreign matter in fuel strainer
Remove sediment bowl, empty it and replace it.
54. Engine Knocks or Develops Excessive Noise
Probable cause
Possible remedy
Improper grade of fuel
Drain and fill the fuel tank with the proper grade of fuel.
Governor not set properly for existing load.
Adjust governor setting.
Engine operating under heavy load.
Turn engine with hand crank, with ignition off, to
determine excessive load due to unusual cause.
Defective oil pump.
Report to organizational maintenance.
Ignition timing advanced too far.
Report to organizational maintenance.
Loose connecting rod.
Report to organizational maintenance.
55. Engine Stops
Probable cause
Possible remedy
Faulty ignition
Check magneto (para. 87).
Erratic fuel flow.
Check feed to carburetor.
56. Engine Oil Pressure Low
Probable cause
Possible remedy
Defective oil pump
Report to organizational maintenance.
Restricted oil lines
Report to organizational maintenance.
Oil too light
Check for diluted oil and replace with proper grade.
Oil level low
Fill crankcase to specified level with proper grade of oil
(L05-3825-221-15).
57. Engine Overheats
Probable cause
Possible remedy
Oil level low
Replenish the oil supply (L05-3825-221-15).
Air shrouding removed or obstructed.
Replace air shrouding and remove obstruction (para. 68).
Engine idles too slowly
Adjust the idle speed (para. 77).
Magneto spark improperly timed.
Adjust magneto timing (para. 87).
58. Engine Exhaust Smoke Excessive
Probable cause
Possible remedy
Oil or carbon piston ring
Report to organizational maintenance.
59. Pump Fails to Prime or Deliver Rated Capacity
Probable cause
Possible remedy
Suction valve set incorrectly.
Move the suction line lever to open.
Suction strainer clogged
Remove and clean strainer.
Loose suction line connections.
Check and tighten all connections.
Suction check valve defective.
Report to organizational maintenance.
Defective pump
Report to organizational maintenance.
Damaged or impaired impeller.
Report to organizational maintenance.
Air leak at pump shaft seal.
Report to organizational maintenance.
60. Little or No Water From Spraybar
Probable cause
Possible remedy
Spraybar valves not set properly.
Set spraybar valves correctly.
Defective water pump
Report to organizational maintenance.
Defective valves
Report to organizational maintenance.
AGO 6871A
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