Installing Harley-Davidson Sportster Evolution Spark Plugs

Removing and installing the front and rear spark plugs.

  • Author: Eric Essen
  • Time required: 30 minutes
  • Difficulty: Moderate
  • Add Note x

This guide will show how to remove the old spark plugs, check the new spark plugs for installation, prepare the spark plugs for installation, and reinstall the new spark plugs.

Tools
Relevant parts
first image

Add Note Edit Step 1 — Spark Plugs  ¶ 

  • The spark plugs are easy to spot on the left side of the motorcycle.

  • The procedure for removing the spark plugs is the same for both the front and back cylinder, and either spark plug can be replaced first. This guide will show how to remove and install the spark plug in the rear cylinder.

first image
thumb image 1
thumb image 2

Add Note Edit Step 2 — Removing the old spark plug  ¶ 

  • Carefully remove the spark plug wire. Do not pull on just the wire, squeeze the spark plug boot, and pull it together with the wire.

first image
thumb image 1
thumb image 2

Add Note Edit Step 3  ¶ 

  • Use an 11/16" spark plug socket to unscrew the spark plug by turning in a counter-clockwise direction.

    • Some aftermarket spark plugs that fit the Sportster use a slightly larger 18mm spark plug socket.

  • Remove the spark plug from the cylinder.

Next » « Previous

Comments Add Note Comments are offturn on