Theres a restrictor tab in that carb in the bottom of the bowl that needs to be removed with a dremel...The tab holds the float too high so the fuel just dribbles past the needle causing a fuel starvation problem when coming off the throttle after a highspeed run.......
after you remove the restrictor tab set the c-clip on the needle to the 4th notch,,float at 10 degrees and the a/f mix screw to 2 1/2 turns out.....