Riding my bike....and it dies. Help?

[Morrider]

OK so first off I should note that my '06 GZ 250 is my very first bike and I am a huge newbie when it comes to this stuff.
So please bare with me and my lack of proper identification of the bike parts.

I purchased my bike around August of last year and the previous owner, from what I was told, kept the bike out in the weather, unprotected, for quite a period and rarely rode it. It is evident, however that the bike was not taken care of very much. The first time I changed the oil, hardly more than a few drops came out.
My first warning came the second time I changed the oil, when, again, it was nearly empty. Ive found no sign of oil leakage anywhere on the bike or the ground where it is parked.

As well, there are times when it can take nearly 5 minutes to(cold) start the bike (and yes i put a new battery in when I purchased it). I have to toggle the choke and sometimes it will start with choke on or off.

OK so to the main point. A few days ago I took my bike for a ride; it took a while to get it started but once I did, it seemed to run normally. I rode a few miles down the road, got the bike up to speed (around 55 mph) and the engine began skip ignitions. As if fuel wasn't getting into the cylinder. For the next few seconds the engine would skip, run, skip, run until finally it lost all power and I coasted to the side of the road. As i coasted, i tried to start the engine again with the clutch pulled but it wouldnt start back up. I pulled over and got off to check out the bike, and it had plenty of fuel in the tank; as far as i could see no fuel was leaking anywhere. After looking over the bike for a few minutes i tried again to start the bike and it started up so i turned around and headed back to my house. Along the way it died on me two more times.
If I had to throw in any guesses, Id say maybe a clog in the fuel line? I'm doubting this is any relation to my previous start up problems or oil issues.
Finally: I tried to start the bike the next day and it did pretty easily but died on me after about a quarter mile. I feel I should note that the exhaust pipes coming right out of the engine were incredibly hot and slightly multicolored, while the engine itself or oil tank were still cool.

Help or suggestions would be greatly appreciated please!!! If there's any more that need be clarified or explained I can do so in a reply. Thank you!