whenever i hit the brake in my volcano for more than a second it stalls at any speed making high speed driving impossible (to stop) any advice on tuning for this problem would help.

maybe try raising your idle.

Adjusting your Idle screw in maybe 1/4 turn should help your problem. What's happening is, when you hit the break it's closing the carb too much and not letting any air in the mix and it's stalling. I had this problem on my buggy yesterday so I adjusted my Idle screw and everything was good after that.

If i turn up the idle any more it wont stay still at idle, but i'll mess around with it some more.

your idle's good if it stays still, it's your low end needle, it's too rich