Generac — Clean Engine Spark Plugs and Set Gap
Maintenance
From a Generac owner's manual covering: 9592, GN-570, Q-55G, Q-70G. Check it applies to your exact model before use.
Applies to: Generac 9592, Generac Q-55G, Generac GN-480 engine, Generac GN-570 engine
Before you start
- DO NOT BLAST CLEAN SPARK PLUGS.
- Sparking can occur if wire terminals do not fit firmly over spark plug terminal ends; reform terminals if necessary.
Parts for this job
- R45S Spark plug — Generac 9592 Amazon eBay $32.56
- 072347 Spark plug — Generac Q-55G eBay $1.99
Part numbers from the service-parts lists for Generac 9592, Generac Q-55G. Verify against your serial number before ordering; some links are affiliate links.
Procedure
- Clean engine spark plugs and reset gap to 0.030 inch (0.8 mm) every 100 hours of operation.
- Clean by scraping or wire brushing and washing with solvent.
- Do not blast clean spark plugs.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Spark plug gap: 0.030 inch (0.8 mm)
- Every 100 hours of operation
Full service-parts list: Generac 9592 →, Generac Q-55G →
Source: Generac 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.