I have a p650 and a friend has a Grizzly 660. When we race The prairie will win but the confusing part is the Grizzlys speedo will say 68 at the top end and the Prairie will say 63, but the prairie is still pulling away. What is more likely, Is the Grizzly reading high or is the prairie reading low? We both have 26'' tires and stock wheels, we have traded bikes and ran so I know hes not lying and the result is always the same. Prairie wins but the speedos say he is going faster, even if we start at close to top speed.

 

His probably reads high AND yours probably reads low. There is almost always a difference between displayed and actual speed, and that's before you take into account tire size... Get a GPS and you'll know how fast you're actually going.

 

get out the radar gun.

 

Yamaha speedometers are notoriously "enthusiastic"!![img]i/expressions/face-icon-small-wink.gif[/img] You sell more machines if you can claim your machine is faster.

 

When my 650P says 63mph the GPS reads only 56.9mph

 

I don't think any of the speedos are really correct.. A GPS or a radar gun is probally the best way of finding out the truth

 

Thanks for the replies guys, dont have a radar gun so I guess I will get out the GPS.