I bought this motor that the previous owner said had a leaking neutral switch causing low oil level. Two of the shift forks galled in their channels on the gears. The gears turned black and blue and seized on splined shafts making it unable to shift. I guess the lesson learned is keep an eye on oil level and if you see smoke coming out of the breather hose, shut 'er down. :sad:
Yikes! Pays to check a bike over now and then