Just bought a 1994 kx80 a week ago for $150. The guy didn't have it long and put it in storage for about 6 months because it stopped running. It's actually in great shape and the top end on it looks brand new. I put a new spark plug, air filter, chain and sprockets on it. I also cleaned the carb and plastic welded the cracked gas tank. After only a total of $250 invested including the cost of the bike, it cranks up perfect and idles too. Completely rideable, except when I first went to ride it! I let it warm up and then as soon as I put it into gear it shut off. I tried over and over and it kept on doing it. I then decided to rev it a lot when I put it into gear and it worked so I took off, but the bike rode extremely slow even while revving high and died out on my real quick. Also it sounds a little like a knocking noise on it but I just now checked the top end and I don't see any scratches or anything. It still looks perfect. Anyone have any ideas why it's not running right? I'm ready to ride!