Stock belt is Bando 23100 KEC4 9000, but it seems short, because there's still a lot of drive face that never contacts the belt.
I tried a 821 20 30, but it was too long and flapped around.
I'm getting a 815 20 30 which will be 6mm shorter, so we'll see if that works, for $15.
I think the stock belt may be 803 19.5 28, which is short and shallow, but those belts are about $50 from Carlos at autotech355 in Taiwan.
Contact him on ebay, he'll sort you out.