I bought this bike:

http://www.nsr250.net/forums/viewtopic.php?t=6812

When I went down to look the bike over the owner informed me the bike hadn't been started in 3 years. We got her running, but not very well. The bike would die with any throttle. We both figured this was due to bad gas and dead battery. I decided to go ahead with the purchase. First thing I did was order a new battery. So I got the battery in flushed the tank and pulled the carbs for a clean and put in new spark plugs.

I figured this would remedy the issue, however it did not.

When I get it up and running the front cylinder doesn't seem to be firing or at least the exhaust pipe from the front cylinder stays cool to the touch even after several minutes of running. The rear exhaust pipe does warm normally. It will only stay running on full choke. At one point I got it to take some revs, then the engined revved out of control and kept running even after turning off the kill switch and disengaging the key entirely. After a few seconds it slowed and died. It has done this twice now. I also notice it seems to run better when sitting on its kickstand and when I get the it upright or even lean the bike over to the non kickstand side it really spits and sputters and wants to die.

I know this is a broad question and could mean many different things, however I have never owned a 2 stroke and know little about them. Anyone ever have this happen to them? What was the solution? Ideas and thoughts welcomed.