You know the other thing I've seen is $hit in the main jet circuit or the parts just not working right.  It's happen to 3 or 4 bikes.  We break down the carb, clean it, never find anything and put it back together and it works, problem solved?

Maybe if you messing with the jets pull the whole assembly apart, needle jet, the jet needle, and the main and spray a little berrymans chemtool in there and make sure they are unblocked and clean, no dirt, no sand.