Re: Speedometer shows too much
Bikes are notorious for having inaccurate speedometers. However, that's quite a bit. An example is if my speedometer reads 75 mph, I'm actually going 68 based on a GPS on the bike. I suspect that someone has changed the sprockets on your bike, which is a common thing. It's easy to count the teeth on the rear sprocket (or look for a number stamped on the sprocket). The front one you'll have to remove the sprocket cover which is held on with bolts.
Anyone can drive a fast bike, few can drive a bike fast!