Sounds like you have too big squirters... you can use a single strand of 18 guage wire looped through both ends of the shooter as a easy way to close up the hole. If your not familar with what a shooter is... it is mounted top center just below the choke air horn. A single screw mounts the thing. If your at all conserned about loosing the wire... where can it go, when both ends are being pushed against simultainously. I had run this before for many years as a tuning trick.

Also check the throtle cam lob... if it has a quick open when part throtle then replace it with a gradual slope. That should clear up the sudden dump of fuel.