Generac — Spark Plug Gap Adjustment / Replacement
Maintenance · Spark plug(s)
From a Generac owner's manual covering: GT-990, Model 004666, Model 005011. Check it applies to your exact model before use.
Applies to: Generac GT-990 engine
Before you start
- Do not blast the spark plug(s) to clean.
Procedure
- Clean area around base of spark plug(s).
- Remove spark plug(s) and check condition; replace if worn.
- Check spark plug gap with a wire feeler gauge, bending ground electrode.
Tools required
- Wire feeler gauge Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Set plug gap at 0.50 mm (0.020 inch)
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.