Mercruiser prop questions

[EarestTBass]

I've got a '88 5.0 Mercruiser, WOT has been about 4000 @ about 40 MPH on speedo with only me on board. I haven't had a chance to verify either tach or speedo since the season is now over. It's a little sluggish to get up on plane. It also had a hydrofoil on it which I've now taken off.

I pulled the prop & it's a SS prop & inscribed "Precision Prop Turbo M 141/4X22 7-5-H".

A picture of the boat is in the second post down.
http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=1;gtid=1165997;pagenumber=3

If the instruments are right, what would be the best step to get the WOT up where it needs to be & help it get up on plane a bit faster? I don't think the boat has the room for trim tabs.

I plan on using it mostly for tubing & skiing.

Thanks.

 

[QC]

Re: Mercruiser prop questions

Yeah, Earest, if the tach is right and after looking at your boat, you need somewhere around a 19 inch pitch and it appears you have a 22. I'll bet you'd pick up a lot on the bottom end and probably a little on top with a change. I am guessing that your wide open throttle range is supposed to be 4200 - 4600. That's a lot of boat for a 5.0 and a 22 . . .

Not sure where you are, but you need to ask around at a couple of local shops to see if there is somebody who has a prop return policy. Most good places will allow you to exchange an undamaged prop. You need to: a) verify your tach and b) test something around 19 inch, maybe a 4 blade.

 

[Crownie2]

Re: Mercruiser prop questions

I agree with QC.

 

[EarestTBass]

Re: Mercruiser prop questions

you need somewhere around a 19 inch pitch

That's what I was looking for, I wasn't sure which would be best & not to much, a 19 inch or 20 inch pitch. The 22 was on the boat when I bought it, I'll keep it for an emergency backup. I'm guessing the previous owner had installed the hydrofoil to try to compensate for the wrong prop.

Thanks!