If you are shifting into OD in the quarter you are definately overgeared, it reads that way from you first post??
I don'y think the carb is terribly too small, not enough to kill that much power, but it does sound lean compared to how most of the 750 VS carbs I've used on similar engines for several people, larger 4 sizes all the way around is close to where I would expect to end up after tuning.
I would have thought the wideband would show some kind of variance during a run, no 3310 is that linear a fuel curve, maybe your O2 sensor is too polluted??
The carb is too small but I don't think just that is killing 1 full second, but maybe it is 2-3 tenths each wrapped up in several small bits you'll find by tuning?? I would definately try a bigger carb if you could borrow one, it could point you in the right direction real quick if it makes a good difference.
So, maybe 2 tenths carb size, 2 tenths timing(seems a little high total, try 34-36°) 3 tenths jetting, 1 tenth launch technique(finding the sweet spot at the line w/engine), 1+ tenth finding perfect shift points(try lower rpm shift to second to work the torque, higher rpm shift to third to use upper rpm HP) .
Add them all up and you are where you want to be. I never really worry about the first few passes, they're just to get a baseline to work from, now you have to test to tune your combo. I don't think there as any "silver bullet" single part here.
Last edited by ericnova72; 05-10-2010 at 05:42 AM.