I have a 3x9-7/8x10-1/2 ,, runs great with me and the dog. but when I add my about 180lb boyfriend bad, bad, bad,.. I can't get going at all, lots if slipping and no planing, takes what feels like a lifetime to get planned out and when I do I'm at top speed... I have no gages, so all reference material only tells you how to jug on rpms, not on the behavior... I have 1 in room on ? .. I have 2 propellers picked out.. that I could wast money on not knowing.. 3x9-7/8x12 quicksilver black diamond $87.49 or 3x9-7/8x9 sr-michigan wheel $94.99.. but I'd prefer to buy one, planning on upgrading to new boat soon.