I dont know if you guys know this,but you can convert your front dif. to a locking one very easily and cheaply.
I know this works on 2001 and oldler 300/250 with the siver colored front dif. (In 2002 artic cat went to a black painted dif. and I have not tried this on them yet.)
This 2001 and older dif. actually has a locking feature already in it, all you have to do is remove the 2wd-4wd leaver from the dif. arm and you will see that there is one more position besides the 2wd-4wd.Move the small arm on the dif. forward one more click and there it is. All you have to do now is make your control rod about 3-4 in longer and get just the right curve to it so it doesnt rub on the frame or brake line and now you have 2wd-4wd or 4wd lock for free!
Be carful to keep your speed down while in lock mode as the Cat only wants to go straight and will have very heave steering, kind of like a Honda has all the time.
Volvoman

 

You can't lock a 02 250/300 due to the fact Cat used their own diff not a Suzuki King Quad's.