A banshee engine builder that did Pikes Peak hillclimb for years told me he jetted richer on the right side because of higher heat from gearbox oil on the right side. As if jetting wasn't already hard enough there.
When 2 strokes got really fast in the 60's it took a while for the engineers to learn how to design a gearbox that didn't generate too much heat. Some did and some didn't so they figured it out pretty quick. Kevin Camerons story of the first KR250 race bikes with compact cases around the gearbox that looked really cool but got so hot the paint came off comes to mind.
When 2 strokes got really fast in the 60's it took a while for the engineers to learn how to design a gearbox that didn't generate too much heat. Some did and some didn't so they figured it out pretty quick. Kevin Camerons story of the first KR250 race bikes with compact cases around the gearbox that looked really cool but got so hot the paint came off comes to mind.