need to know what size, thanks

 

Depends on the year, but it might be a 25x10-10 (25 diam, 10 inch wide, 10 inch rim).

You should get later prairie wheels on it, so you can use the 12" tires that everyone else uses. Then you could use 25x10-12 tires. The Prairie 650 wheels fit my brother's P400, so I do believe they will fit the P300. They are relatively inexpensive, lightweight aluminum.

 

NYROC is correct, the bolt pattern & offset will work with the other Prairie wheels... that is one of the best performance mods we've done to our '01 - 300 Prairie, was to install the stock wheels off my 650 Prairie ( the stock 300 wheels are steel, & the stock 650 wheels are light weight aluminum )... this helped alot with acceleration on the 300 ( my wife is the mud bog queen on that quad )... & while there are a lot more tire styles available for the 10" O.D. rims, there are advantages of running the 12" O.D. rims all the way around... I.E. more clearance around the rear drum brakes... by the way, the bolt pattern is 4 on 137 for both the fronts & the rears...