Prop advice?

P

Prop Novice

Recruit
Joined
Sep 29, 2011
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2
I have a 1996 Bayliner 2252 Hardtop with a Mercruiser 4.3L Alpha one. Takes 4000 rpm to stay up on plane and redlines at 4600. I want to reduce revs yet stay up on plane (about 20mph), Any advice or suggestions for a prop that do this would be most welcome.
Thanks
 
S

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Prop advice?

Please read (read this first)at the top of the page.
Do you have the speed at 4600?What size prop?Usually near the base of the blades or under the prop nut.Is it slow to plane?
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Prop advice?

Takes 4000 rpm to stay up on plane and redlines at 4600.
Click to expand...

4000 rpm to stay on plane???? Do you use your trim at all, or just leave it all the way down?
 
P

Prop Novice

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Joined
Sep 29, 2011
Messages
2
Re: Prop advice?

At 4600 I'm at about 29 MPH. Not sure of prop size. I will have to take boat out of the water and look .. as lower leg won't completely take prop out of water. It does not take long to plane.
 
S

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Prop advice?

Something is screwy.It would take a 13" prop to get 29 at 4600. Thats a prop you would find on a very difficult boat to push like a pontoon or small houseboat.Is your speed by gps?Do you trim down for slower speeds?
I think your tach may be off.Most likely you have a 17 or 19" prop
A 17 would produce about 37 at 4600.maybe slightly less on your boat.
Check the setting on the back of the tach operate the switch a few times to clean the contacts.Be sure its set for a 6 cylinder.
 
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