Or a stuck float, or a float with a pin hole leak allowing gas to fill up in it and keep the float in the downward postion...I have had both happen to me a few years ago.
He said gas was coming out of carb and exhaust. That's why I thought rich
The issue is that the point at which the carb mounts to the engine wasn't sealed causing a vaccum pulling in excess fuel causing the spark plug to get wet and stop producing spark. the old carb is on now and it works flawlessly. Need to adjust the throttle cable though sit idles1st thing I think of when it won't accelerate is fuel flow issue, restriction. Not that is the issue here just my 1st thought.