Automobile Information & Articles

The key to simplifying the mixture setting puzzle is to first understand that the combustion cycle produces heat, and that the amount of heat concentrated around the spark plug changes proportionately and quickly with changes in the air / fuel ratio. Therefore, the best way to know the mixture is to be able to "see" the mixture! This may sound a little strange, but the color of the flame produced around the spark plug during combustion changes as the mixture changes. Typically, if you could see the flame color it would be a hot blue when the mixture is just right, a yellow when it is too rich (more fuel than required for any given amount of air) and a white/blue when the mixture is too lean (less fuel than required). Interestingly these changes in flame color occur very quickly as the engine operating condition is altered, such as when the throttle is opened, when load is applied or during deceleration.

Conventional wisdom leads most to believe that proper mixture adjustment is simply a matter of setting the number of turns on an idle mixture screw, but unfortunately carburetors and fuel injection systems need to adapt constantly to changes in operating condition and therefore have a number of operating circuits and components in an attempt to target the proper mixture under all operating conditions. Having the ability to see the combustion process would allow the tuner to both pinpoint problem areas during a diagnosis as well as to experiment with changes in settings and components to optimize performance.

The Colortune product line is structured around the concept of tuning by "reading" the combustion flame color during actual engine operation. The Motorcycle Colortune is simple to use, and works with single or multiple carburetor and fuel injected bikes, ATV's, snowmobiles and personal watercraft.

You can even "balance" the mixture correctly between cylinders on multi-carburetor engines! The kit includes a special view-through sprark plug, high tension lead adapter, 2-piece viewerscope with mirror, copper seal washer, cleaning brush and complete instructions.

Procedures for setup and use are simple. After warming up the engine, remove the spark plug in the cylinder that is to be checked and replace it with the Colortune plug. Now attach the included high tension lead between the plug and the boot end of the spark plug wire (it will work with either terminal nut ends or plain threaded terminal configurations). Run the engine and observe the color through the insulator area of the special plug while performing your adjustments. For difficult-to-access spark plugs, the kit includes a 2-piece viewerscope with an attached mirror. The viewerscope is placed over the Colortune plug and lead, such that the combustion color can be observed at practically any angle!

Colortune is the essential tool for fast and effective tuning!

Article source: The Eastwood Company