WARNING
Disconnecting spark plug cable with engine running can result in electric shock and death or serious injury. (00464b)
CAUTION
Do NOT pull on any electrical wires. Pulling on electrical wires may damage the internal conductor causing high resistance, which may result in minor or moderate injury. (00168a)
Check the spark plugs at the specified service intervals. Refer to Maintenance Scheduling → Service Records.
1. Disconnect spark plug cables from plugs by pulling up on the molded connector caps.
2. Remove the spark plugs.
NOTE
Use only specified Harley-Davidson spark plugs.
3. Use a wire-type feeler gauge to gauge the spark plug gap.
a. Select the gauge with a wire size that is within gap specifications. Refer to Specifications → Specifications → Electrical.
b. Pass the wire gauge between the center and the outer electrodes.
c. If necessary, use a gapping tool to bring the gap to within specification.
4. Apply ANTI-SEIZE LUBRICANT to the spark plug threads.
NOTE
  • Spark plugs must be tightened to the torque specified for proper heat transfer.
  • If a torque wrench is not available, tighten new spark plugs finger-tight. Then tighten an extra one-quarter turn with a spark plug wrench.
5. Install the spark plugs. Tighten.
Torque: 16.3–24.4 N·m (12–18 ft-lbs) Spark Plugs
6. Connect each molded connector cap until the cap snaps firmly into place over the spark plug.