I recently acquired a '96 zx6rF as a project track bike off a mate who gave up trying to get the thing tuned/fuelling correctly. He had a bike shop go over the carbs, had a Dynojet kit put in, still no good, then back to stock, he had it on a track and ran ok then would run rough on 3 pots.
Bike has stock carbs/jets, K&N filters, full Muzzy exhaust, otherwise stock.
I am learning about carbs as I work on this bike so by no means am I experienced but that was part of the reason for getting it as a learning tool.
I said I'd take it off his hands for a project, silly me, and have since pulled the carbs apart, checked float levels, reset pilot jet screws to stock settings, checked main jets, all stock, checked needles - they have the 5 height positions on the needle with settings at 3rd ring.
What happens is the bike takes a while to start using choke, running quite rich, as it slowly warms and I gradually turn down the choke, I have to turn up the idle screw to keep it running. For a short while during all this it actually revs quite well, until finally dying down and stalling. Then I can't get it going again! When revving it up it will occasionally have a slight lag in dropping the revs (pilot jets?) and other times rev smoothly until finally bogging down.
Now, if I could get pics on here again as unable since using an iPad!, It would show on no.1 carb a crack/chip on the lip of the casting where the diaphragm sits, where the black cover screws down to cover it. Hope this makes sense without a pic. As far as I can see it doesn't affect the seal of the diaphragm but not sure under operation.
Any ideas (hopefully the bleedin' obvious!