Are you referring to the Dellorto carb?
If so, try a search for Adam85's post with a dyno run and air/fuel mixture graphs. Or maybe Adam85 will be kind enough to repost for us.
Most of us with the Dellorto have found the pilot jet to be excessively lean.
I found that a 48 pilot works well up to approximately 8000'ASL (2850 M ) with temps in the 70's F. (21 C) At higher elevations, it was slightly rich, but not excessively rich. And it only showed symptoms at very low rpm's grunting up steep hills. Nothing too severe that a little clutch dab couldn't correct the problem. At lower elevations, 2500' ASL ( 900 M ) it works well up about 105 F (41 C). At 115 F (46 C) it shows signs of being slightly rich.
Currently, at 2500' ASL, our temps are 70F to 80F ( 21 C to 27 C), it seems to be perfect, mixture screw is only 1/2 turn out. As the temps drop in the next month, I will only need to open the mixture screw to compensate.
Bike starts first kick most times with this pilot.
2000 miles on the original spark plug, never fouled yet.
I also increased my main jet to 195 and I raised the needle clip, dropped the needle lower, one notch from standard.
I found the Dellorto to be very easy to tune and to possess the ability to accurately meter the fual through an extremely broad range of temps and elevations. I have friends with jap bikes that have to rejet far more frequently to just keep their engines running.
I also found the bike runs much more consistently on Aviation fuel than on pump gas. I use 101 low lead, the engine seems to run cooler and is more powerful than when using pump gas. Probably due to pump gas having so many emission control additives. I have run av gas back to back with race gas (110 oct leaded) and found absolutely no performance difference in either fuel.
