Prop for 16' aluminum boat

MacM

Cadet
Joined
Dec 1, 2005
Messages
9
I recently bought a 16' aluminum boat, the boat is a Duranautic weighs 320lbs. I bought a new Yamaha 25hp four stroke tiller as well, I think the factory prop that comes with it is 12p, I was wondering how this would be and if I could gain anything by switching to SS prop with a higher pitch, it would seem the boat is pretty light for the standard pitch. I will not be able to try the boat for 5 months so I was just curious if anyone had any experience with a similar setup.
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Prop for 16' aluminum boat

You won't know unless you have a tach. You want to shoot for max recommended RPMs with a normal load. Without that data, it's a crapshoot.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,559
Re: Prop for 16' aluminum boat

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. <br /><br />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. <br /><br />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.<br /><br />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. <br /><br />Course without a speedometer, once you are moving along above 25 mph (on a good plane), a few mph here or there are unnoticable.<br /><br />HTH,<br /><br />Mark
 
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