Spark Plugs

Motorcycle spark plugs: what they are and how to choose them

Spark plugs create the spark that starts combustion in gasoline engines. Their condition affects starting, smooth running and engine response, so choose them according to the specific requirements of your motorcycle. This category covers electrical and ignition system replacement parts. Do not confuse spark plugs with spark plug caps, which connect the high-tension wire to the plug itself.

To choose the correct replacement, consult the owner’s manual, technical documentation or the reference number on the installed spark plug. Check the engine type, thread, diameter, threaded length, seat type and heat range specified by the manufacturer. It is also important to verify the electrode design and gap when specified by the manufacturer. A part with different dimensions or characteristics may not fit correctly or could affect ignition.

Checks before replacing a spark plug

• Identify the exact reference recommended for the motorcycle and the applicable year or version.
• Visually compare the thread, reach and terminal with the removed part. Do not assume that two similar spark plugs are interchangeable.
• Inspect the spark plug cap, wire and mounting area before installing the replacement.
• Install the part following the procedure and tightening torque specified by the motorcycle or spark plug manufacturer.
• If the removed spark plug shows deposits, wear or an unusual color, investigate the cause before simply replacing it.