Actually mfr pressure suggestion is for what they believe to be for the best ride. It may vary. Learned that when at a Bridgestone tire seminar for Honda when selling bikes and parts. Kinda cool.

They, a bunch of tire guys, were at a meeting at Continental's plant in Europe when they got the bright idea to see how much air the tires would take. They attached an air chuck to one, got a good clear distance from the "experiment" and put the air to it. It was either 285 or 385 psi when it blew - the rim broke!

 

Its a nice looking rack KLX250. Thanks for the link!