The valve adjustment would be the first thing to check, but you said you did that. I say check them again. Step two, you sound lean since you can put on the choke without that showing up in blubber. So, also check the adjustment on your compression release to see if its out of adj and or malfunctioning. Make sure there's a tad of play in the pull to ensure its sitting all the way home. Now, since you cleaned and reinstalled the carb, check to see if you maybe have the boot on incorrectly with an air leak. Next, check to see if the float got back in right and is not sticking. If your fuel flow is short, you can run the bowl dry with the lean-cough-stall condition. Seems unlikely and stuck bowls are usually stuck open, not half closed, but I'm working up the ladder. Another way the flow could be limited is by something in the float needle area. So recheck that. Another possibility is the fuel flow to the carb is restricted due to some from of blockage such as dirty petcock, pinched hose, cracked (& leaking) fuel hose. That's about all I can think of. Good luck, Ned.