I recently rebuilt the carb on my 1976 40. After fixing the float level and getting it within the little dot on the glass, the cruiser rev's very nicely and idles fine. But when I go to drive it, it sputters and almost dies. The only way to get it up to speed is to pump the throttle. I suspect that the secondary is not opening. Could this be my provblem? I have also tried leaning it out and richening the mixture screw, it seems to run better when leaned out, but still sputters and has not power or smooth acceleration.