I'm back and I think we can solve your problems. First I would like the shrouds back on. When you turn the high speed needle in it is very common for the speed to increase. I WOULD LIKE YOU TO FIND A VIDEO ON THE WEB ON HOW TO SET THE GOVENOR BEFORE YOU GO BACK AFTER THE CARB. It is very difficult for me to explain with out pics. Sorry. After setting the governor, start with step #3 again. The stalling you experienced is probably due to a too lean mixture, as you thought. (Before looking at your pics I assumed that you had a large one-piece Flo-Jet carb) If I was correct you will just follow my past instructions. It will have a high speed needle coming in from the bottom. Looking at the top pic of the carb, you have two adjustments on the top. The one with the spring is the idle mixture needle. The other one is the high speed jet, leave it alone. IF I GUESSED WRONG AND YOU HAVE A SMALL ONE PIECE FLO-JET CARB, you will not have a needle on the bottom. In that case the needle closest to the air intake is the high speed needle and the other is the idle needle. Just follow the steps, but the needles are in different places. Go slow, if you feel that the engine is revving too high either bring the throttle down or stop and we'll start over in another direction. Good luck.