Removal Procedure
- Remove the spark plug wires. Refer to 
Spark Plug Wire Replacement.
 
- Loosen each spark plug one or two turns.
 
- Brush or air blast away any dirt from around the spark plugs.
 
- Remove the spark plugs one at a time and place each plug in a tray marked with the corresponding cylinder numbers.
 
Installation Procedure
- Properly position each spark plug washer.
 
- Inspect each spark plug gap. Adjust each plug as needed.
 
Specification
Spark plug gap: 1.524 mm (0.060 in)
Caution: Refer to Fastener Caution in the Preface section.
- Install the spark plugs.
 
Tighten
|     •  | For IRON Head-all Subsequent Installations tighten the spark plugs to 20 N·m (15 lb ft). | 
 
|     •  | For new iron heads tighten the spark plugs to 30 N·m (22 lb ft). | 
 
- Install the spark plug wires. Refer to 
Spark Plug Wire Replacement.