I finally got my first atv a couple months ago. Its a late 2004 sportsman 700efi. Ive been doing a lot of plowing lately and was having trouble going in 4x4. I've read through the forum and decided to change all fluids before tearing into the gearcases(good thing cause it looked like they were filled with chocalate milk). That seemed to help alot, but when i was working on it , noticed i'm running two different sized tires. 25-8-12 in front 26-12-12 in rear. Is that normal?or what am i ruining by running this?