prop question

[johnmcmanus]

I am restoring a 1982 20 SF SeaCraft with a rebuilt 1993 150Hp Evinrude. can anyone tell me what should the prop pitch be, Im guessing 19 pitch but im just guessing.

[johnmcmanus]

what is the best way to determin what prop to buy

[Old'sCool]

Lots of variables but 19 is a good start. Try several

[eggsuckindog]

19 should be right - look for a used Stilletto and mount it high if you find one

[McGillicuddy]

Well, asking for suggestions is a great start.

Do you have a prop now? If so, what kind of performance are you getting.

19p is logical for 150 hp on a 20, but the style of the prop is also important and often overlooked - depending on the shape you may only be able to get a 17p to target rpms. The benefits of a stern-lifting prop has been emphasized repeatedly for SeaCrafts so I'd look for a prop that promotes that attribute.

Props can get pricey and there is no sense in buying a bunch of them trying to get it right. I see $500 props for sale all the time because they weren't right for a particular boat. Ask the owner at a local prop shop to loan you a couple on successive weekends to try out a few.

The basic idea is to find a prop that will spin up to the high end of your motors rpm range with your boat loaded with people, fuel, gear, etc.

Other elements like the shape of the prop also have a lot of impact on your overall ride and performance. The old OMC "SST" prop has some clout here.

Another overlooked aspect is the motor height. SeaCrafts tend to run most efficiently with the anti-cavitation plate about 1 to 2" above the plane of the keel. Good luck

[eggsuckindog]

Want to change my post, if you find a Stilletto it should be a 17, they are very aggressive and my 200 can barely swing a 19

[workinpr0gress]

Got a 15x17 sst and it runs great on mine I would probably rather have 19p of the same prop but I get a little more boat out of the water with the bracket than most other people and no ttop. I can spin 5600 at full trim full of fuel and a couple guys. I hit almost 6000 light on fuel and by myself which is way to much for a Crossflow.

[76Red18]

Depending on which model 150 you have, I would say a 19 could be way to much. A 60 degree and 90 degree block 150 are different animals entirely. A 60 degree likes to run really "loose" ( Don't overload it). It should hit 5500 rpm fully loaded. A 90 degree block can handle a little over propping but should still be able to reach the upper end of max rpm range.
I have a 60 degree 150 on a very heavy 18' cc. The best prop set up that I've found is an old style OMC SST 15" x 15" with the motor's av plate at 1.5" above the keel. I'd go higher but she looses water pressure.