broken fins pic test

[DeanR]

First try at posting a picture. If it works I'm just wondering if the broken fins are just cosmetic or does it affect cooling?

[Ken Talbot]

Picture works okay. I'd have to say that amount of breakage would only be a problem cosmetically. I'm sure Yamaha designed the fins to look after some very severe running conditions with a substantial factor of safety. The amount of breakage here looks like a pretty small percentage of the overall cooling surface of the engine.