I have noticed a step or mismatch that exists between a cylinder exhaust opening and exhaust flange. The exhaust flange opening will typically be round and the mating opening in the cylinder will be "D" shaped. It seems to be rather deliberate and I have witnessed it on a CR125, TM125 and a RS125. I found a reference to this "step" here. http://www.bonavolta.ch/hobby/en/moto/rs125r.htm ---1/3rd down the page.---
Q: What is the purpose of this step?
Thanks,
Koryo
Q: What is the purpose of this step?
Thanks,
Koryo