Cummins/Onan — Pre-Heating and Starting
Operation · Generator set
From a Cummins/Onan operator's manual covering: 12.0 DJC, 4.5 DJB, 4.5 DJE, 6.0 DJB, 6.0 DJE, 9.0 DJC. Check it applies to your exact model before use.
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Before you start
- Do not use ether as a cold weather starting aid
- Do not apply overvoltage to the starting circuit; use a 12 volt battery connected in parallel
Procedure
- Engage Preheat switch 60 s if ambient 55°F (13°C) or lower, or 30 s if above
- Engage Start switch and hold Preheat until engine reaches operating speed
- If engine fails to start after 15-20 s cranking, repeat steps 1 and 2
- Release Preheat switch after engine reaches speed
- Check oil pressure gauge reads at least 20 psi (138 kPa)
Specs & values
- Oil pressure at least 20 psi (138 kPa)
- Starter disengages at approximately 900 rpm
Source: Cummins/Onan operator'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.