44. Engines Miss or Vibrate Excessively
Probable cause
Possible remedy
Faulty carburetor ................................ ....................... Replace defective carburetor (paras. 86 and 93).
Governor out of adjustment ................................ .......Adjust the governor (paras, 87 and 94).
Leaking fuel line................................ ......................... Replace defective fuel line (paras. 85 and 92).
Faulty distributor points ................................ .............Replace distributor points (paras. 99 and 125).
Distributor not timed properly ................................ ....Time distributor (para. 99).
Defective spark plugs ................................ ................ Replace spark plugs (paras. 100 and 127).
Broken fan ................................ ................................ Replace fan (paras. 146 and 157).
45. Engines Stall Frequently
Probable cause
Possible remedy
Idling speed too low................................ .................... Adjust idling speed to a minimum of 600 rpm (paras.
Operating water temperature too low ......................... Replace thermostat (paras. 150 and 155).
Governor hunting ................................ ...................... Correct governor adjustment (paras. 87 and 94).
Defective carburetor ................................ .................. Repair carburetor (paras. 300 and 383).
Defective distributor ................................ .................. Repair distributor (paras. 324-326 and 399-401).
Defective valves ................................ ....................... Replace or repair valves (paras. 171 and 174).
46. Engines Overheat
Probable cause
Possible remedy
Loose fan belt ................................ ........................... Adjust fan belt (paras. 145 and 157).
Defective thermostat ................................ ................. Replace thermostat (paras. 150 and 155).
Collapsed hose or loose hose connections ................ Check condition of hose. Tighten hose connections.
Replace defective hose (paras. 148 and 153).
Coolant low in radiator................................ ................ Fill radiator with proper coolant.
Insufficient oil in crankcase ................................ .......Check oil level; fill as necessary (LO 5-3810-227-15).
Water pump and generator drive belt loose or slip.....Adjust belt. Replace worn or damaged belt (paras. 104
and 131).
Faulty water pump................................ ...................... Replace water pump (paras. 149 and 158).
Thermostat defective ................................ ................ Replace defective thermostat (paras. 150 and 155).
Hose leaks ................................ ................................ Tighten clamps. Replace defective hose (paras. 148
and 153).
Loose or open drain plugs ................................ .........Inspect and tighten. Replace defective drain plug.
Fan belt loose ................................ ........................... Tighten fan belt.
Defective radiator ................................ ...................... Replace radiator (paras. 328 and 407).
Defective water pump ................................ ................ Repair water pump (paras. 332 and 411).
47. Excessive Black Smoke From Exhaust
Probable cause
Possible remedy
Faulty carburetor ................................ ....................... Replace carburetor (paras. 86 and 93).
Air cleaner clogged ................................ ................... Clean, air cleaner. Replace a faulty air cleaner (paras.
Excessive oil in crankcase ................................ .........Drain oil and fill crankcase (LO 5-3810-227-15).
48. Engine Temperature Fails to Rise
Probable cause
Possible remedy
Thermostat defective ................................ ................ Replace defective thermostat (paras. 150 and 155).
Defective temperature gage ................................ ......Replace temperature gage (paras. 107 and 135).
49. Engine Starts but Will Not Run
Probable cause
Possible remedy
Low compression ................................ ...................... Adjust valve clearance (paras. 171 and 174).
Defective carburetor ................................ .................. Replace carburetor (paras. 86 and 93).
Air intake clogged ................................ ...................... Remove obstructions (paras. 84 and 91).
Defective fuel pump ................................ .................. Replace fuel pump (paras. 88 and 95).
Defective distributor points................................ .........Replace distributor points (paras. 99 and 125).
AGO 6819A 68
