check your thottle linkage, I had a V-spec that leaked really bad out the carb slide and filled the rubber boot and it would run down the carb, it was caused by not having a straight pull on the slide, I drilled a new hole in the servo horn and remounted it, and to my surprise it quit leaking, ran that engine the rest of the season with no problems
just an experience once for 2 cents
Make sure the carb is seated all the way down too, you really have to push down to get a good seat and get the top oring into the crankcase and hold it there and tighten the carb retainer bolt.