I'm curious as to your asking.
Recently I was working on a friends bike. His original slide in the matched body was too slack and it rattled. I fitted a good slide in the body and it nipped up. It was obvious that the body was warped as well as the slide being excessively worn.
Slides are fairly inexpensive so I would start by checking the bore is round. If you have a known good slide, you can:
1) cut away the locating nib and the bottom of the slide so the bottom is flat, then open up the needle hole large enough so it will sit over the spray tube.
2) get some bar at the correct OD to match the ID of a good body, and fit that into the bore ( I think John has done an article on bringing the bodies back to true. )
Until you know your carb is true, measuring clearence might be a waste of time, as you could have good clearence in one spot, but it still can suck air.
The friends carb I mentioned earlier was running lean ( the engine was fitted with a big bore kit, so we took carb settings as red) we were up to a 190 main jet and looking at going richer before I noticed the slide issue, after fitting a gknown good carb, we were back to a 160 main jet which was the same as a standard setup.
Last edited by Allan Gill; 11/14/13 6:47 am.