My 07 has 14 hours on it....the chain is trash, the rear sprocket is trashed, the fork seals are leaking a lil, the front "strong" excel rim has two dents in it, and the gytr skidplate didnt fit worth a shit. I am not new to bikes and i am a nut with maintenance. My 04250f has stock "generic" rims with no dings...and they've gotten some real abuse especially when i had to ride home with a flat. The fork seals never leaked one bit either. The stock chain and sprockets lasted atleast a lil longer than the 07...and 90% of these hours are pit riding, not even teh mx track. I know the yamaha powerplant is still supposed to be the most reliable but i could have gotten a honda or kawi for 1500 less. Im almost regretting my purchase. I called yamaha and they really didnt seem sympathetic of my situation which angers me even more considering this is my fifth yamaha. Sorry guys, just need to vent.
IMHO you should re-think the title of your post. It gives a wrong impression to people casually perusing this board. None of your "problems" really fall under the category of reliability and one might argue almost everything you are bitching about is self inflicted.
Sorry if I offend you, but that's my opinion - worth all of $0.02.