the ONLY bike I have ever had problems with was a Honda. Not saying its true for everyone, but my cbr 900rrs motor blew, twice, my little xr100 that I had as a kid had to have the carbs cleaned if the bike sat for more than a week, and of all the yamaha's I currently, and previously have owned, not one has ever, EVER broken ANYTHING.

this is my experience, yours may vary.