I agree with Willy. As far as where are you with the prop you have, I'd say it depends on what the mfgr was thinking when he installed that prop. He may have been propping for general conditions considering the engine could wind up on a planked oyster skiff or on a lightweight aluminum boat like yours. In that case you could up the pitch and get some more performance.
On SS vs Alum, my experience is that the SS wins hands down on performance and durability. With 25 on an 16' boat you could mess with props and not buy yourself much in performance (durability, yes). Now if you had 50 or 60 hp on that boat, then you could definitely tune up your performance.
I just bought a 17' alum with a pad hull with a 90 hp on it. It weighs 750" and I just re-propped it and it runs at 49 with a 21" Ballistic, with just me in the boat. Not too bad for a 90. That's why I said that the 25 isn't going to get you much in the way of performance.
One quick test to see where you are is to load the boat normally, and from a standing start hit the throttle wide open. If the boat planes out in like a second, you could probably use more pitch and pick up a couple of mph. On the other hand if it takes 2 to 3 you are probably pretty close and when you tear up the prop that's on her now you could reprop with a ss.
Course without a speedometer, once you are moving along above 25 mph (on a good plane), a few mph here or there are unnoticable.
HTH,
Mark
Prop for 16' aluminum boat
Linear Mode
