To start with, yes... if you find that you've opened the high speed needle out more than 2
or 2 1/2 turns, and it's still doing it... I'd screw the low speed needle out about 1/8 turn,
and start over. It could also be some air leak, or that you've roasted the piston/sleeve,
but we'll keep our fingers crossed for you By friend's started doing the same thing,
after running it without tank pressure (broken cap) and getting it extremely lean.
Now, it runs fine for a few minutes, but quits when it's warmed up.