picked up a 94 f2 for 500 bucks and the guy said its been sittin for 2 years and he couldnt get it running. when i got it home i sprayed ether in carbs and it popped here and there so i knew it was firing. then i had a friend crank it over while i sprayed at the same time and she fired up and has been running since. i had the carbs off and noticed the intake valve in cylinder 3 was leaking by. when i roll on throttle it is smooth but as soon as i cruise at 4000 to 5500 or so rpms it jerks like crazy. you can hear it in the exhaust almost sounds like a misfire but not quite.. kinda hard to explain. it has a k&n and a full vance and hines ss2 exhaust and my friend said it looks like stock jets because the needles arent adjustable?? so wondering if the carbs just need to be tuned or if leaking intake valves will make it run like that. i pulled the plugs and they were a good cardboard brown color they were not white or anything like that. it just stinks because i dont have the money to do trial and error and i have a feeling im going to have to sell it

 

Take it to a bike shop and have them assess it. At least you'll have a good second opinion. The news may not be good if you've got a bent valve and this is unlikely but go through a process of elimination via a good starting prognosis. Even bike shops are there to help, not just grab your wallet.
I'd wager a carb problem. Dirt and crap after it's long sit. Check the valve clearances though.