I'm curious about tire pressures and water/mud riding.I've got 27" Zillas and run about 6lbs of pressure but in water on my SP500 I cannot get the front to rise,I tend to ride the bottom unlike my partner's Sportsman 500 that stands up in the water

 

I take it you're shifting your weight towards the back of the quad? Does your riding partner have bigger tires. It's not so much the air pressure as the size of the tire. Each size up and wider will give more flotation. What width are your Zillas? How do they compare to your buddies tires size wise.