Hello Thumper, Thank you for the welcome. Usually, if bikes are jetted too lean at an idle, they will tend to search up and down in the RPM range and you will generally have an inconsistent idle as the engine is searching for gas. With that said, have you done the old "sustain 50MPH ,pulling in the clutch and hillting the kill switch, and immediately check your plug?" (I'm hoping you've pulled over to the side of the road) I think your bike is too lean, I had the same problem. I was running a 125 main and the are screw turned out 1 and 3/4 turn and the needle lowered one notch and when it got warm the bike would pop on deceleration. Jetting is certainly a black art, but at least I have a great collection of jets ranging from 112 to 130. Maybe I'll make my wife some earrings!!
Lot of good info in this thread. Question, if I was to lower input restriction to the carb by simply switching over to the K & N type air filter, would I need to go to larger jet? Also, If i did go to a larger jet and the air filter conversion, would I need to open up the exhaust. In other words are all the elements of the open air modification required for it to work right?