Cummins/Onan — Starter Maintenance
Maintenance · Starting system / cranking motor
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan MCCK
Before you start
- Never oil the commutator. Oil on the commutator reduces cranking ability.
- Never use emery cloth.
Procedure
- Periodically lubricate, inspect brushes and commutator.
- Periodically disassemble cranking motor for thorough overhaul.
- Lubricate oil-type bearings with 8 to 10 drops of light engine oil (SAE 20).
- Give oil-less type bearings and bushings a few drops of light oil.
- Lubricate cranking motor drives with a few drops of light engine oil.
- Never oil the commutator.
- Clean commutator with number 00 sandpaper; never use emery cloth.
- If commutator is out of round or has high mica, turn it down on a lathe.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan MCCK →
Source: Cummins/Onan service 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.