Honda EG3500X — Spark Plug Service
Maintenance
For the Honda EG3500X, from the Honda owner's manual.
Applies to: Honda EG3500X, Honda GX240 engine
Before you start
- Muffler will be very hot if engine has been running.
- Never use a spark plug of incorrect heat range.
Procedure
- Remove spark plug cap and use spark plug wrench to remove plug.
- Visually inspect plug; discard if insulator cracked or chipped.
- Measure plug gap with feeler gauge.
- Check washer condition and thread plug in by hand.
- Tighten with spark plug wrench to compress washer.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Gap 0.7-0.8 mm (0.028-0.031 in)
- New plug: tighten 1/2 turn after seating
- Used plug: tighten 1/8-1/4 turn after seating
Source: Honda 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.