I wondered if it wasn't an odd size...I didn't take the time to look it up though...we were only a Kawi dealer for 2 years before I left...just not as familiar with these as some of the Honda and Yami stuff...and even some of those memories are starting to fade to be honest
Here's mine from like 2 years ago, with the newer bigger tires and wheels. Iirc they are like 11" and most use 12" rims now. They are a common bolt pattern though and new kawis use this. 4x110 off the top of my head.edot... 4WD, 89-05 (F) 24x8x11 4/137 front Bayou 300 4WD, 89-05 (R) 24x10x11 4/137 rear Use this chart, you'll see newer bigger kawis use the same 4x137 bolt pattern. mine were from a brute force 650 iirc and 25" od tires. 1" lift this way and gets rid of the odd 11" wheels. But now I have to have the rest tire chains tight or they clip the metal stay on the foot guards. Kawasaki Tires and Wheels Application Chart
As long as you keep the front to rear "ratio" the same, shouldn't cause trouble. I upsized the tires on my Grizz and there was some binding on dry pavement...I played with air pressures until it felt about the same in 4x4 as 4x2 (on dry pavement) which is probably better than 99% of the quads out there with stock sized tires...due to people not paying attention to tire pressure and as I'm sure you are aware, a couple PSI difference in a 2 ply tire can make a big difference in overall diameter.
I just took a a look at eBay and see a set of 4 same size as the factory ones that are on it… $244.99 free shipping. I can probably live with that. But have other things demanding my $$$ for a little bit
Keep looking. CL and fbm. Wait to find takeoffs from a brute force like I did. Someone will want bigger fancier wheels and tires and you'll be able to buy them for less than that and they'll be newer, and better, and you'll be done with 11" wheels.