My daughter has been racing in Briggs Cadet for a year now and recently we bought a 2nd engine so that we have dedicated dry and rain race engines. Her original engine has never been quite the same since we ran it in rather heavy rain (with an intake filter cover of course) at a Ron Fellows race earlier in the year (another reason we wanted a 2nd engine). We had the engine freshened up and dyno tuned and while the results are decent, it still doesn’t seem to be quite as strong as it used to be down the straights. The tuner set the float height to .900", which I just measured to confirm, but since we recently went to a 15deg mount, I got to thinking how that may affect float height tuning.
If the carb and therefore the fuel bowl are tilted, won’t the leading float be pushed up by the fuel sooner and close the valve sooner than intended? Also the fuel that is in the bowl might not be as close to the main jet compared to if the carb was level. Does this mean that a .900" float height might end up being more lean than intended? I have leveled the bowl as much as possible while still keeping the carb outlet opening aligned/unobstructed. I haven’t noticed any cutting out or stumbling but even after a full day at the track the spark plug has absolutely zero carbon build up on it - it looks brand new. That seems a bit lean to me.
I’ve only been working on my kid’s kart for about a year now and while I love every second of it, carb tuning still feels like a bit of a mystery to me. I’ve read quite a few posts on carb tuning but still have a lot of questions. I’m used to tuning DI via software