1985 bayliner capri 2.1 volvo penta 270 sterndrive

[Stworsen]

Ok guys, i had a spin and bent prop on our boat. it used to WOT at about 5000 but now with the new prop (1/2" bigger) the new WOT is about 4400 at about 33-35 mph. Is this good or bad? Does it matter?

 

[Don S]

Re: 1985 bayliner capri 2.1 volvo penta 270 sterndrive

Your WOT (wide open throttle) range for that engine (assuming it's an AQ125A) is 4500 to 5100 rpm.
Too much prop and you are lugging the engine. You need to get a prop the same size as your old one.

 

[steelespike]

Re: 1985 bayliner capri 2.1 volvo penta 270 sterndrive

What size is each prop. what was the wot rpm and speed with each? As long as your going to be getting a prop perhaps we can
tweak things a little.

 

[Stworsen]

Re: 1985 bayliner capri 2.1 volvo penta 270 sterndrive

I went from a 14.5 to a 15 inch. What can we tweak?

 

[steelespike]

Re: 1985 bayliner capri 2.1 volvo penta 270 sterndrive

We need the diameter (and)pitch of the props. Hopefully you can remember the old prop rpm and speed as well as the new.
A gps is best for speed.
Normally a 1/2" change in diameter will result in about 100 rpm change.
Tweaking would involve your present performance numbers.Like if you had high slip, try to g figure why and perhaps a prop change. Not enough rpm or too much rpm.Solving slow hole shot or excessive bow rise.
With those numbers we may be able to tell if your setup works.