RE: Exhaust deflectors
I do the the same as Campy with one groove. It's also a good idea to use a wire so you don't loose it if it comes off. There is a filet in the elbow of the extension. Put a small hole in it and attach a string or fishing leader. Then attach the other end to the engine mount. Four stroke mufflers get hotter than two stroke mufflers. It may melt no matter what you do.
david