cb500t sputters at high rpm

[hansimusmaximus]

my cb500t runs GREAT at any rpm below about 5500, after that it starts to stutter badly and won't climb any higher. would could be the cause of this??

 

[Swagger]

Dirty carbs....or.......leaky vaccum bellows

 

[Useful Idiot]

My 75 does the same thing and if I run it right under the 'sputter' rpm it will eventually die after a couple miles. I'll pull over for about 5 minutes then it fires right up.

Just guessing, I think it's the coils getting too hot. I want to put a electro setup on the bike just so I dont have to time it all the time (and see if it fixes this problem)