I was thinking that by changing the tire size larger or smaller that I could get a little more top speed. I'm also going to be installing a K&N air filter on this machine. The reason that I need to any performance mod's is so that I can have a fighting chance against my friends that ride 400 Xplorer/ 400 Scrambler.

 

Save your money, It won't make that much difference. A 300 will never keep up with a 400 on top end. Maybe for the first 50 ft. bu that's it.