Have you tried the gas cap trick, yet? Ride the bike with an extra key in your gas cap, and as soon as the bike starts running like crap, open the cap. If the bike starts running normally again, the vent in the gas cap, or one of the gas tank vent lines is blocked, and needs to be cleared.
BC.
I didn't do it, I swear.
And even if I did, what makes you think I would admit it to you?