Problem that's baffled me... It starts right up and runs fine for about 30 seconds to a minute, then it acts like i have thrown the choke on. It starts spitting, sputtering, and throwing black smoke, generally stalling but not dieing. After doing this non-stop for about 3 minutes it then just clears up and runs fine! However, yesterday after mowing with it for about 20 minutes it started acting up intermittently at the end too. While it's choking out I can move the choke lever and it only makes it worse. I checked the linkage on the carb to make sure that the choke was totally open and it is. I thought the first time it happened it was just an isolated incident, maybe a bit of dirt in a jet or something, but it does this every freaking time I need to use it! I just don't see that it can even BE the carburetor causing the problem... I thought maybe it could be a switch or something (this is on a small walker mower) but if it was a switch I would think it would either work or not and not. Iv'e wiggled wires, unplugged and re connected harnesses and switches while it's running bad and nothing seems to help. I'm off now to see if I can find a carb kit for it, maybe the needle or seat isn't sealing good? Of course, since it's on a walker it's a b$^%* to get to anything, I hope I don't have to pull the engine to get the carb off! Anyone have any suggestions???? Thanks!