Gunson - G4171 - Motorcycle Colortune Kit 12mm

Specially designed for motorcycle engines, this low volume Colortune maintains the compression ratio of the engine, ensuring better firing of the mixture. Simple to use, the Colortune spark plug has a glass insulator viewing window so that the combustion flame is visible. The kit also includes a viewscope with adjustable mirror so that the flame can be seen where engine access is restricted. The colour of the flame inside the cylinder shows the richness of the air:fuel ratio. A yellow flame indicates a rich mixture, a blueish white flame a weaker mixture whilst a Bunsen blue flame is usually correct - by adjusting the mixture screw the correct flame colour can be attained and the engine tuned accurately. This motorcycle Colortune kit is designed for use with a 12mm spark plug size.