so i was talking to some of my friends and hes got a 06 r6 50th edition. and he was saying that from the factory yamahas are about 13% off, has anyone heard of this or know if its true with hondas or all bikes

 

All bikes, like cars, are off somewhat. But you will hear different things. It depends on speed as well too. Under 100mph you are about 7-8% off, and once you start peaking that, you get to about 10% or so, but again, it depends on who you hear it from.

 

Honda F4i's seem to be about 7mphHIGH on the speedometer when going about 70.
When it shows 77 you actually going about 70.