do you have any mods or is this 450 completely stock? sounds lean if it runs better w/ choke ON. but then it would more likely backfire on acceleration. anyway... check for an intake air leak. are your bands tight around your insulator(front of carb) and your connecting hose(rear of carb) to air cleaner. check fuel tank breather and carb air vent hose. float level could be low or clogged fuel line. these are just some things that could cause a lean mixture. again, i don't think it's a rich mixture prob. when did prob. start?
oh yeh... has anyone touched your mixture screw? i think it should be 1.5-1.75 turns out from factory. you must turn it all the way in first though, but not tight. hope this helps... keep us posted schindog. did you get your lights off yet?
