Everyone knows what a spark plug does. But many
questions are asked about why certain attributes of the spark plug exist.
Here is a spark plug FAQ that answers these
The ability to read spark plugs can
tell your or your mechanic a lot about the state of tune of an engine and about some of
the problems an engine may be experiencing. In the absence of other more sophisticated
equipment, the simple act of removing the spark plugs and examining them under a low power
magnifying glass can help jet the carburetor, set ignition advance, recognize additives in
fuel and many other conditions. While no one can learn to read spark plugs by simply
studying a short article like this, you can learn the basics. We have
provided two guides to reading spark plugs. The first guide provides
information provided by the spark plug
manufacturer, the second guide was created by an experienced
motorcycle tuner. Reading both will provide you with insight into the
art of reading plugs.
When you need to make serious horsepower, sometimes
you need to make adjustments to the spark plugs. Indexing
the plugs and adjusting the plug gap
can add a few extra horsepower to your engine. Here is some additional
information on getting that last little bit of power from your engine.
V-Twin Café provides a spark plug application and interchange chart for
Harley-Davidson motorcycles, including 80 CID Evolution engines, Shovelhead engines and
all Sportster engines