Harley-Davidson, the motorcycle manufacturer, partners with various renowned spark plug manufacturers to produce spark plugs specifically designed for their motorcycles. These spark plug manufacturers include well-known companies like NGK and Champion. Harley-Davidson ensures that the spark plugs meet their stringent quality standards and are compatible with their engines. It’s recommended to use spark plugs recommended by the manufacturer or available through authorized Harley-Davidson dealerships to ensure optimal performance and compatibility with your Harley-Davidson motorcycle.
the spark plugs on a Harley-Davidson motorcycle:
Step 1: Gather the necessary tools and supplies Before starting, make sure you have the following items handy:
- A set of new spark plugs specifically designed for your Harley-Davidson motorcycle. Consult your motorcycle’s owner’s manual or check with a Harley-Davidson dealer for the correct spark plug specifications.
- A spark plug socket wrench or a deep socket wrench with an extension.
- A spark plug gap tool (if necessary).
- Dielectric grease (optional).
- A clean cloth or rag.
Step 2: Prepare your workspace Choose a well-lit and clean area to work on your motorcycle. Ensure that the engine is cool to the touch before proceeding.
Step 3: Locate the spark plugs Refer to your motorcycle’s owner’s manual to locate the spark plugs. In most Harley-Davidson motorcycles, the spark plugs are typically located on the cylinder heads, accessible through the spark plug wires or coils.
Step 4: Remove the spark plug wires or coils Depending on your motorcycle model, you’ll either have spark plug wires or individual ignition coils connected to the spark plugs. Carefully disconnect the wires or coils by pulling them straight off the spark plugs. Avoid pulling on the wires themselves, as this can damage them.
Step 5: Remove the old spark plugs Using the spark plug socket wrench or deep socket wrench with an extension, loosen and remove one spark plug at a time. Turn the wrench counterclockwise to unscrew the spark plug from the cylinder head. Take note of the condition of the old spark plugs for reference.
Step 6: Inspect and gap the new spark plugs Examine the new spark plugs for any signs of damage or defects. Check the gap between the electrode and the ground electrode (the curved part of the spark plug) using a spark plug gap tool. Adjust the gap as per the specifications mentioned in your motorcycle’s owner’s manual. Some spark plugs come pre-gapped, but it’s always a good idea to double-check.
Step 7: Install the new spark plugs Carefully insert the new spark plug into the spark plug socket or deep socket wrench. Gently hand-thread the spark plug into the cylinder head to avoid cross-threading. Once it’s hand-tight, use the wrench to snugly tighten the spark plug by turning it clockwise. Be careful not to overtighten, as it can damage the threads or the spark plug itself.
Step 8: Reattach the spark plug wires or coils Reconnect the spark plug wires or ignition coils to the new spark plugs. Ensure that they are firmly seated and securely attached, but do not force them. If using dielectric grease, apply a small amount to the inside of the spark plug wire boots before connecting them to the spark plugs. This helps with moisture protection and ease of future removal.
Step 9: Repeat the process for remaining spark plugs Follow the same steps (4 to 8) for each remaining spark plug on your motorcycle. Take your time and work carefully to avoid damaging any components.
Step 10: Clean up and inspection Wipe off any dirt or debris from the surrounding area using a clean cloth or rag. Double-check that all spark plug wires or coils are securely connected.
Step 11: Test and start the motorcycle Once the spark plugs are installed, start your Harley-Davidson motorcycle and let it run for a few minutes. Listen for any unusual sounds or misfires. If everything sounds and feels normal, you have successfully changed the spark plugs.
Remember to consult your motorcycle’s owner’s manual for specific instructions and recommended spark plug specifications. If you’re unsure or uncomfortable performing the spark plug change yourself, it’s