So I had to split my cases for a unrelated problem and while I was taking out my transmission I noticed that on the primary shaft 2nd gear and 3rd gear had some problems. The bike has been shifting fine but i knew that these two gears where on their way to failure soon. The cogs are in perfect condition, absolutely nothing wrong with them, so its not my shifting thats screwing it up? The teeth have spots in them indicating wear. Its really hard to explain, its almost like the metal is porous? And I can take my finger and flake off the smooth "coating"(?) around the porous part. Has anyone ever taken an X ray of these things? I know the older Yamaha 's had transmission problems, maybe this is the reason? Im just looking for A reason as to why this keeps happening. Once again the cogs are perfect and the bike shifts fine until the teeth bust off the gear. And Im only seeing it this time on the primary shaft, the driven shaft looks perfect.