How can I tell if my motorcycle is running rich?

Answer by  Amber40 (24961)

The most accurate way to tell this is by using an o2 sensor in the exhaust. This will measure the oxygen content of the exhaust to determine it's air/fuel ratio. However this can be expensive and requires modifying the exhaust. You can try reading the plugs. Black greasy carbon indicates too rich rich and very white typically means lean.

Answer by  Amber40 (24961)

The easiest way to tell is by looking at the plugs. A bike that is running rich will have black oiling looking plugs. A lean engine will have white burnt look. Normal running engines should have a clean plug.

Answer by  Amber40 (24961)

The easiest way is to inspect your spark plugs. A rich engine will have dirty sometimes greasy or wet black deposits. White or excessively burnt plugs indicate a lea condition.