Harley-Davidson® Spark Plugs Replacement

We're gonna start with spark plug replacement. Gonna always wear safety glasses anytime you're using compressed air. Gently blow out any debris that may have accumulated around the spark plug area. Remove the spark plug wires. Please note their location. The new bikes are single-fire ignition. Spark plug wires must stay front and rear as they're placed. With a standard ratchet and a socket, remove the old spark plugs and discard them. When it comes to spark plugs, Harley-Davidson plugs only are recommended. There are no substitute. If you wanna play with your spark plugs, hotter flame, longer travel, they do offer platinums, double-platinums, and screaming eagles. Although a bit more costly, they are worth the money in many applications. For this service, we're gonna use this standard Harley-Davidson original replacement plug. Most plugs, single electrode, are factory-gapped, but you definitely always like to double-check the factory gap due to shipping problems or just someone's bad day. Gap on a plug should be 38 to 40 thousandths. You notice there's a number of gap gauges, from a standard slide gauge, to a wire gauge, to a normal feeler gauge you would use in a number of applications. Again, we like the Loctite stick. It's handy. Put a small dab of anti-seize. This'll keep the plug from overheating and sticking, freezing into the head. Always re-thread the spark plug back into the engine by hand, and then torque it to the proper torque spec, which would be 12 to 18 foot-pounds. During this operation, it's always a good idea to check spark plug wire routing, not only under the fuel tank, but to the coil, and proper connections and clean connections to the end of the plug and to the coil. After you re-torque the spark plug, re-install the front and rear spark plug wires in their proper locations, and your spark plugs have been properly serviced.