To adjust the float height you can buy one of the gauge from faster motors but I would recommend investing in a digital caliper. Your float height is measured with the carb upside down from the flat of the carb to the top of the floats. B&S recommend 0.870 but I’ve seen floats set anywhere from 0.850-0.890. The tricky part is remembering to think backwards when making the adjustment. The lower you make the float height the richer the mixture will be and leaner with a higher number. “Most” of the time you can do some testing and see where your engine seems happiest and that will give you a good base. From there each race day you can adjust the A/F screw to fine tune the carb or change ne the needle height in the slide for a bigger change.
The biggest thing to remember is there is not going to be a magic bullet with these engines. 95% is down to chassis, tuning, and driver.
I have no idea about the relationship between jet changes versus float level changes. I know with a .038" jet, an increase in diameter of .0002" is close to a 1% change in hole area.
A jet only changes the mixture in a certain range.
Floats change the mixture over the entire range.
So if you change a jet and floats you have altered the direct relationship between the 2 jet sizes. IE: you made 2 changes. Then if you are not measuring your fuels specific gravity you may have a variable there.
With floats you would have to establish a baseline and go from there. I think that is where someone who owns a dyno can get a very small advantage.
Before you go into EGT tuning:
34. Exhaust Header
g. Any modification for or use of an O2, EGT, CO2 sensor is prohibited.
So not on race day. I’d say you can do it on a practice day. There is a probe to stick in exhaust but the length is not correct. A spare exhaust could me modded. I think it would be effective to get some good data as long as you make note of all the correlations.
Yeah I’m not impressed with the gauge.
Plus I keep a caliper in the tool box anyway.
And yes thinking backward or upside down is a must.
Just not having the carb corroded up puts you 90% there . . . .