Colortune is a unique mixture setting device and a detector of other mixture related problems. It is a spark plug, which runs the engine like any normal spark plug, but because it has a glass insulator, it allows the colour of the combustion flame inside the cylinder to show through andindicate the strength of the mixture.
How Colortune works:
Combustion at its most efficient produces a clear blue flame, various colours result in inefficient mixtures. Inside an internal combustion engine those same colours are present though not normally seen. With Colortune fitted in place of a spark plug, the flame is visible through the glass insulator and the fuel is ignited by the spark in the Colortune.