I have never noted any sludge or crust build up on the inside in that pipe area on my bike or on Serenity's old 57,000 mile engine.

I theorize that the double wall exhaust pipe stays cool enough that the radiant heat simply warms the aluminum cases some then the heat is conducted away by the aluminum housings and the oil pool behind them and is expressed out into the air as general radiant heat from the whole lower engine.

These aluminum case areas are backed up by the oil pool in the sump and the circulation filled oil filter cavity so you can see it would be kinda tough to locally overheat these side case areas as they have places to conduct that heat away to that are nice and ready at hand.



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Bill, Charon has been gone for about 6-8 months now and he was on your side for the first 2-3 oil wars, so please quit kicking about his opinions on gasoline and gearing during a current oil war.    

As far as you working on a bike to change the gearing, how many years ago was that?   20-30 years ago?

Focus on today ....  say something good about Klotz that can be verified or say something bad about Rotella that can be proven.