thanks for the input, you seem to have the same problem, the problem i have is 60 mph is 60 mph, do not care what you ride or drive, by federal law it should at best be only 1 to 2 mph +\-, so in my case and yours, i am racking up more miles on the speedo than the bike has traveled, also if you get stoped for speeding, have fast are you actuly going? i am doing everything i can to get this fixed
I am a bit anal (get your mind out of the gutter...) and I would very much prefer my speedo to be accurate, but I have been down that same road you are on many bikes ago and much like you are finding I was never able to get it factory repaired and grew tired of the effort.
I agree with Funk...
every bike I've had has had the speedo off by 3 or 5 mph. All research I did led me to believe that getting the manufacturer/dealer was not really possible. If you have an electronic speedo, there are electronic devices that will allow you to adjust you indicated speed. Otherwise, research getting slightly larger height tires to also attempt to correct the speed error.
I called Yamaha, if greater than 10% off; they'll fix it. All the bikes I've owned have read fast. Even the $18,000 09 max was 6.2% fast; put a speed-o-healer on it. Can't do that with the 650, like said before, just a taller tire. Also, your MPG is less than what you calculate from the speedo reading.