Timbo wrote:
I have a colourtune, its fun and looks nice, but it really only helps with the mixture at idle, you can't use it under load where you really need to get the mixture spot on. It won't help you much if you haven't got the correct needle to begin with.



Not quite right. It can be done under load. Vizard and at least one or two other people has written how to do it. (Got the articles somewhere) Without the all the details and safety aspects and driveshaft angles, etc, the very, very bottom line is jack the front of the car up, start it running then use the brakes to put it under load while pushing down on the accelerator to keep it from stalling. Done it a long time ago more than once. It works.

There's the other "under load" test where all you (very basically) need is a pencil in the carby piston but I haven't tried it yet. Got the book, sounds a great idea, very simple and costs nothing. It shows you where to modify your needle to whatever your engine wants it to be. If the needle can be modified that far which would generally be true as your standard needle would require more enrichment that leaning out if you've modified the car. But my wife says I'm constantly wrong so don't take my word.

smithy