Cummins/Onan — Setting Ignition Coil Air Gaps
Adjustments · Ignition magnetos
From a Cummins/Onan service manual covering: 5.5 HGJAA, 5.5 HGJAB, 5.5 HGJAC, 5.5 HGJAD, 5.5 HGJAE, 5.5 HGJAF, 6.5 HGJAA, 6.5 HGJAB, 6.5 HGJAC, 6.5 HGJAE, 6.5 HGJAF, 7.0 HGJAA…. Check it applies to your exact model before use.
Applies to: Cummins/Onan 5.5 HGJAD, Cummins/Onan 5.5 HGJAE, Cummins/Onan 6.5 HGJAE
Procedure
- Bar the engine until the lands on the flywheel directly face the coils.
- Place a 0.012 inch (0.03 mm) thick feeler gauge between the coil and the land.
- Hold the coil tight against the feeler gauge and land and torque the two mounting bolts to 5 lb-ft (7 N-m).
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Air gap 0.012 inch (0.03 mm)
- Magneto mounting bolts 5 lb-ft (7 N-m)
Full service-parts list: Cummins/Onan 5.5 HGJAD →, Cummins/Onan 5.5 HGJAE →, Cummins/Onan 6.5 HGJAE →
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.