Helllo, i have a BSA 441 "Desert Sled"(see it in my profile), it has a Boyer Ignition, Podtronics rectifier/zener diode replacement, and ive tried three different carbs on it(2 Amals, a 32mm and a 34mm, and a custom billet pumper carb). The problem is it will idle fine, but if you give it any gas it starts to sputter and stumble until you let off the gas. BUT, if you crack open the throttle, and quickly put your hand over the intake and then take it away(to choke it down momentarily), it will rev up fine for a second, then start sputtering again. Anyone have any ideas? Im thinking maybe the ignition coil is bad or something, but i honestly have no clue. thanks <EDIT>When its idleing it runs really smooth and sounds fine. it only has problems when you rev it.