I have a raptor 700r and was wondering what PSI to run in the tires. I am a big guy @ 260 pounds. What would the affects of overinflated or underinflated tires be? I mostly due trail riding. Not into jumps.

 

set em to whatever yamaha recommends-it says on one of the warning stickers on your bike
this psi is good for all types of riding

 

high psi gives higher speeds and rougher ride, lower psi gives better bite and a little more cushiony ride. over inflating is more likely for blowout, under inflating more likely for bent rim. i run mine under 10psi usually. i think latly around 6 or so.

 

I run 5 to 6 on the trails and 3 in the dunes