what size chain does the 250 take. 520 112??

 

520 106 links on 14/42 (stock) gearing on the 07 and earlier models (13/45 gearing you'll need 108 links.)

I'd assume the 09 and later (includes 08) will be the same but not 100% as the newer model has a different swinging arm.

 

My '10 model is the same WestOzKLX - 520 with 106 links (I have a 13 tooth up front, but that makes little difference)