'75 550, complete carb rebuild, tear down full clean, all jets o-rings, everything new. All stock settings. Stock jets, needle on 2nd notch (stock depending on where you look). 4 into 2 exhaust, stock air box, stock filter.....(not new yet though, waiting on that). Valve gaps set. Points, gap, static and dynamic timing all done. Fuel clean and fresh. So it had NO power on first test runs, re-did timing, it was off a tad, now much better but still stumbles on acceleration. With choke partially on it runs much much better. I messed with A/F screws, was at the standard 1.5 out, under assumption that, since adding choke helps, it was lean (choke limiting air thus enriching, yes?) So I went all the way in to 1/2 turn out, no noticeable difference. Just for fun went to 3.5 out (which I believe would be leaning it even more) still can't really tell a difference. Again, adding some choke makes her happy. I will double check for air leaks but unless it's as simple as a dirty air filter (blew out old with compressor and "looks" fine, but a new one will be here tomorrow). Am I looking at jetting up? I spent a lot of time on float height trying to nail it but could be off. I did sync with vacuum gauges as well. I will triple check timing and check for air leaks. All advice welcome.