Cummins/Onan — Normal Starting Procedure (Above 0°C [32°F])
Operation · Engine starting
From a Cummins/Onan owner's manual covering: G 12, G28, G855, GTA12, GTA19, GTA28, GTA855. Check it applies to your exact model before use.
Applies to: Cummins/Onan G 12, Cummins/Onan G&855, Cummins/Onan GTA855
Before you start
- Before starting, be sure that everyone is clear of the engine and the equipment.
- Do not crank the engine for more than 30 seconds at a time; wait two minutes before attempting again.
- Do not idle the engine for excessively long periods of time (more than 10 minutes).
Procedure
- Check the lubricating oil level and engine coolant levels.
- Set the throttle for idle speed.
- Disengage the clutch (if equipped) or open the main circuit breaker on generator set applications.
- Open the gas supply shut-off valve.
- If equipped with a Sentinel safety, turn the cam on the safety shut-off valve clockwise to the open position.
- Push the Reset button on the instrument panel. On low pressure systems, use a gas primer valve.
- Hold in the safety switch override button or turn the timer past 20 seconds and push the start button.
- Release the override button when the oil pressure gauge shows an increase. Oil pressure must be indicated within 15 seconds after starting.
- Engage the clutch, if equipped, and run the engine at just above idle to allow the engine coolant to warm up.
- Idle the engine no more than 3 to 5 minutes at 1000 RPM before applying the load or until the engine water temperature reaches 140°F (60°C).
Specs & values
- Oil pressure must be indicated within 15 seconds
- Maximum 1035 kPa [150 psi] air-gas starting motor inlet pressure
Full service-parts list: Cummins/Onan G 12 →, Cummins/Onan G&855 →
Source: Cummins/Onan owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.