Here are my prop numbers
25x10 XOAR 5740 rpm
22x14 XOAR 6050 rpm
i also have run the 24x12 but have not tached it yet .... I'm going to try a 23x12 next and hope that it will get the speed I'm looking for. The 25x10 seemed to be the best for speed so far. I was actually dissapoonted with the 22x14 ... Not sure why it didn't deliver the speed I hoped for. If you haven't tried the 25x10 yet I would think it would be great on your yak