I've been posting trying to figure out what happened to my bike.  Pablo says vacuum leak and Srinath thinks it's lean.  I just remembered that I removed one of the black covers on the top of the carbs (I guess it lets you access the needles) right under the gas tank.  Under the cover there was this...gasket?, maybe, of flexible rubber and when I took it off a spring came with it.  I thought I put it back exactly the same, but maybe I pinched the gasket, or an o-ring fell out or something.  Does anyone know if, in fact that happened, it would result in severly delayed throttle response and loss of power?  Sometimes I wonder why I get my tools out before I really know what I'm doing, but then I always seem to do it again.  Aaahhh....the learning curve...
 

Gibb

Yup, that could do it. Only one way to find out though...pull the tank off again. Don't put your tools away though. F'in up is how you learn. We've all been there...and some of us still are!!  

Part #26 in this BikeBandit diagram is a small O-ring that could have fallen out and would definitely result in weirdnesses.

That O-ring is the smallest part in this rebuild kit, in case a photo of the actual part would help....