Originally Posted by Chrisbarnes1
ps has anyone messed with the Mikuni settings--I've gone up a jet size and raised the needle a notch to get the best from a more open airbox and exhaust--and then had trouble just off idle--the compensation jetting was off and it sometimes stalls--a good friend (who knows the carbs) said the same happens on the BMW F650--interestingly the cure (which seems to work) is to actually weaken the idle mixture slightly--this seems to allow more fuel for the compensation when you crack open the butterfly--strange--but seems to be true.
I read the same thing in the Dellorto carb PDFs. I was thinking perhaps it was a "flooding" issue, and the smaller pilot jet brings the stoichiometry back into line off idle.
You should post this question into creeper's LC4 setup thread; I can't give you any feedback on your friend's description of why. If you do try to drop a size in the idle circuit jet I'd be very interested in your results.