Carb Tuning Resources

Here are some good explanations and reference to help understand Carb theory (to my mind, about as complex as string theory or quantom mechanics).

Mikuni USA has some good technical info. (It's aimed at Harley, but the theory is the same). Example; the interesting Roll Off test for determinining the size of your main jet.

www.mikuni.com/fs-tuning_guide.html

www.mikuni.com/pdf/vmmanual.pdf

"ROLL-OFF:

The Roll-Off technique is the quickest and is almost as accurate as the Roll-On method. First, one gets the engine warm on the way to a safe roadway. If there is room, use fourth gear as this allows more time to assess the result.

Now, get the engine rpm high enough that it is on the cam and in its power band. This may need to be as high as 4000 rpm with some cam choices. Apply full throttle. Let the engine accelerate for a couple of seconds until it has settled in and is pulling hard. Quickly roll the throttle off to about the 7/8ths position. When you do this, the mixture richens slightly for a second or so.

If the engine gains power as you roll the throttle off, then the main jet is too small and you need to fit a larger one.

If the engine staggers slightly or has a hard hesitation, then the main jet is too large and you need to fit a smaller one."

www.iwt.com.au/mikunicarb.htm Some nice diagrams and explanation of carb theory.

www.dansmc.com/carbs2.htm Another explanation of some basics.

Looks like some good info in there.
Thanks