Why generators show "engine does not start": 18 documented causes and brand-specific fixes, compiled across 16 manufacturers.
Low oil pressure or oil level
2 brands- Gas-KOHLER: Check and refill oil if necessary. Refer to the 'Oil Check' section for details.
- Kohler: Check and refill oil if necessary. Refer to the 'Oil Check' section for details.
(1) Fuel filter clogging. The starter rotates normally but the engine does not start. (2) Clogging of fuel pre-filter (3) No fuel (4) Air entry into fuel line system (5) Nozzle clogging
2 brands- Airman: (1) Disassemble, clean, and change (2) Clean, and (3) Fuel replenishment (4) Bleed the air (5) Disassemble/Clean
- Kubota: (1) Disassemble, clean, and change (2) Clean, and (3) Fuel replenishment (4) Bleed the air (5) Disassemble/Clean
Low coolant level
1 brand- Generac: Check and refill engine coolant to proper level
Incorrect fuel mixture or spark plug problem
1 brand- Allmand: Check fuel mixture and replace spark plugs if necessary
The engine does not reach a speed of approximately 1000 RPM within a few seconds, or the starter engages continuously for over 75 seconds in generator sets with optional overcrank control; or the engine does not run after a second attempt at starting
1 brand- Cummins/Onan: Place the Run-Stop-Remote switch in the STOP position and momentarily press the Reset switch to clear an overcrank fault. Wait two minutes for the starter motor to cool and then repeat the starting procedure. If the engine still does not start, refer to the Troubleshooting section.
Obstructed fuel line
1 brandFault code 0x0001 is present in the ECM memory.
1 brand- DynaGen: Check for proper fuel supply and ignition system. Clear fault codes using a diagnostic tool.
Starter motor operates but engine does not start
1 brand- Yanmar: No diesel fuel - Refuel fuel system Engine control lever not in the RUN position - Move engine control lever to the RUN position Engine oil level low - Check and fill oil to proper level Clogged engine oil filter - Replace engine oil filter Clogged fuel filter - Replace fuel filter Drain the fuel tank and replace outlet manually Poor fuel injection - Compressed air leakage from intake/exhaust valves - See authorized YANMAR dealer or distributor Faulty engine stop solenoid - Engine starts with recoil key switch not in the ON position - Turn key to the ON position Battery needs charging - Check electrolyte, recharge battery Starter motor does not operate or rotates too slowly (engine can be turned by hand) - Faulty cable connection at battery terminals - Clean terminals, retighten cables Faulty starter switch - Faulty starter motor - Engine cannot be turned manually - Inner parts seized or damaged - See authorized YANMAR dealer or distributor
The starter will disengage after a specified period of time and the control will indicate an overcrank fault.
1 brand- Cummins/Onan: Place the Run-Stop-Remote switch in the STOP position and momentarily press the Reset switch. Wait two minutes for the starter motor to cool and then repeat the starting procedure.; Place the Run/Stop/Remote switch in the STOP position and momentarily depress the Reset switch. Wait two minutes for the starter motor to cool, then repeat the starting procedure. If the engine does not run after a second attempt at starting, refer to the Troubleshooting section.
Fuel injection pump malfunction
1 brand- Yanmar: Check fuel injection pump and adjust or replace as necessary
Overcrank fault
1 brand- Cummins/Onan: Place the Run-Stop-Remote switch in the STOP position and momentarily depress the Reset switch. Wait two minutes for the Starter motor to cool and then repeat the starting procedure.
The starter will disengage after a specified period of time and the control will indicate an overcrank fault
1 brand- Cummins/Onan: Place the Run-Stop-Remote switch in the STOP position and momentarily press the Reset switch. Wait two minutes for the starter motor to cool and then repeat the starting procedure
Temperature below 32°F (0°C): Use Number 1 diesel fuel. Use correct viscosity oil. Keep batteries fully charged. Do not use ether starting aid.
1 brand- Cummins/Onan: Preheat cold engine: Push preheat switch and hold - 30 seconds if above 55°F (13°C); 60 seconds if below 55°F (13°C). To start: Release preheat, engage start switch. Limit cranking to 15 to 20 seconds to conserve battery. Allow 1 minute before re-cranking.
Spark plug may be fouled by the fogger
1 brand- Cummins/Onan: Clean or replace the spark plug