How much does 1 jet size affect A/F?

Your primaries are a jet/rod or two rich, remember you want 'a slight hesitation' when the accelerator pump is disconnected, then take it around the block with the accelerator pump disconnected to verify. And yeah, part throttle will be leaner, but it's a step in the right direction. I'd think that it's not going to be a direct ratio to your cruise, try a step leaner to get your off-idle right and go from there. One move at a time. It's a balancing act.

As far as what number your trying to shoot for on the gauge, and how the carb acts, I'd go with what makes the carb and engine the happiest every time.

I'd suggest going in the steps provided on page 9 'tuning for beer'. Start at the front, move to the back kinda thing..


After everything is set-up, and technically tight in the ballpark, THEN fine tune it with the gauge. If your still getting something as wide as 2-3 jet sizes, and deciding on power valves and having lean and right conditions to the point you can find them with low-tech means, you've got to get that ironed out first.

Glad ol' Lars could shine some light here, I love that ****in' paper... Got mine tuned like a damn drum.