Question:
Answer:
What causes spark plug fouling?
Many factors can contribute to spark plug fouling.
Once a spark plug is fouled, it will not provide adequate voltage to the firing tip and the cylinder will not fire properly.
The high energy ignition systems of most modern motorcycles have very small tolerances. All components of the electrical system must work within a specified range for the machine to operate well.
Cleaning spark plugs may have been commonplace 30 or 50 years ago, but no longer. Remember that spark plugs are a maintenance item. They wear out just like oil, chains and sprockets.
In most cases, the spark plug cannot be cleaned sufficiently to restore normal operation. They may last a day or a week, but they will never be as efficient as new. Once your spark plugs have been fouled by oil, carbon or unburnt gasoline they need to be replaced.
In our experience fouled spark plugs are the number one cause of misdiagnoses, confusion and aggravation faced by do it yourself motorcycle mechanics. Just because you replaced the plugs 2 weeks ago does not mean that they aren’t the problem.
There will always be instances when you have to attempt cleaning spark plugs. Such as when you are broken down on the side of the road or the plugs for your vintage machine are back ordered at the height of riding season.
NGK Spark Plugs’ website
states that if you are determined to clean your plugs, follow the following steps:
There are many people, webpages and blogs that will tell you that cleaning spark plugs is cheap and easy. There are ebooks and reports available for sale. Even spark plug cleaning machines or systems you can purchase.
It is our opinion that cleaning spark plugs may be fine for your lawn mower or 1950s Chevy, but not for a European or Japanese sportbike.
Leave Cleaning Spark Plugs for Need to Know