Hope I can help with your tuning problem,go to the 58 slow jet ,next 2mm is way to big of a shim for the needle this will cause a way rich condition,my self on my bike I had to make a shim out of a washer that was 20 thousands of a inch ,my main jet right now is a 180 but I might go one bigger,the bike runs xclnt all thru the rpm range no flat spots ,the only diff my bike has from yours is I have a White Brothers pipe on it with just three disks in it,have no airbox and using a foam uni filter.when you put a shim under the needle you need to make sure that the outside dia is not bigger than the clip or stopper on the top of the needle, if not the needle will not drop down to the bottom of the hole in the slide where you place it, the needle in causing a rich condition , this sounds like your problem