Ibought a 19.5 bayliner with a 1990 115HP Yamaha<br />on the back. It came with a Mercury Quicksilver<br />Prop, 12-3/4"x21. The best rpm's I could get was<br />4500. <br />I then bought a Yamaha 13-19K prop and ended up buying a new thrust washer and spacer so I could use it. The best rpm's I got with it was 5200.<br />I dinged up the Yammie prop and am going to fix it for a spare.<br />But I have an opportunity to buy a 17P Quicksilver<br />Black diamond.<br />Original prop specs called for 13x19, 13.25x17,<br />12.63x21, and 13.5x15 in the aluminum props.<br />So... do I buy the Quicksilver prop? Will the same hub kit fit the 21 and 17" OR do I buy a 17"<br />Yamaha prop? OR Fix the 19" and keep the 21" as<br />a spare? Will the 17" overrev the motor?<br />I am tired of spending money on this part of the<br />boat and would appreciate your advice.