Does anyone know where they sell replacement posts for the bottom of a bruteforce seat?

 

Try Rocky Mountain Atv. They have oem parts available. You may have to buy a whole seat though. Might call them and see if they have the parts you need or contact your local Kawasaki dealer to see if the parts you need can be ordered or if you have to order the whole seat.

 

just checked for mine & looks like the posts are part of the seat
I have the same issue posts are gone. Kawasaki sells the bushings for the posts but not the posts themselves. I am going to order the bushings & make some posts to epoxy to the seat base