Cummins/Onan — Cylinder Head Assembly (BGM)
Repair & overhaul
From a Cummins/Onan service manual — check it applies to your exact model before use.
Browse Cummins/Onan generators & specs →
Before you start
- Do not remove heads when hot; warpage may occur
Procedure
- Use new head gaskets; clean heads and cylinder block thoroughly.
- Place heads in position.
- Tighten all bolts to 5 ft-lbs (7 N-m).
- Tighten to 10 ft-lbs (14 N-m), then continue in sequence to specified torque.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 14-16 Amazon eBay FridayParts $135.00 ft-lb (19-22 Amazon eBay FridayParts $39.99 N-m)
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.