well the weights, spring and muffler are no longer variables.
While tire pressure has effect I say its neglible. If jetting was that sensitive......I would have to jet twice a day one in the morning for cool temps and again in the evening for warmer temps.
Here is a pic of 38/115 jets, no shims. weights, spring, stock air box and homemade muffler. The plug looks fine, its the dam top speed that is bugging me.
This is same setup with 110 jet.
This is stock everything except muffler.