HELP prop for a 165hp mercruiser

[harbolt1]

Hi guys I am new to this site and new to boats. Any help I could gather on here would be greatly appreciated. Thanks in advance. Heres the issue I am having I have a 1976 Ebko boat with the 165hp mercruiser in it. The motor has been completely rebuilt. I put the boat on the water yesterday and at WOT i am only pushing about 2900 rpms. FRom what i have read i should be pushing about 39-4300rpms. Is this correct? I currently have a 14.5inch prop with a 19 pitch. I have been told if I change the prop that could fix the problem?? What should I change it too and how much difference will it make. Thanks guys I could really use your help.

 

[Bondo]

Re: HELP prop for a 165hp mercruiser

Hi guys I am new to this site and new to boats. Any help I could gather on here would be greatly appreciated. Thanks in advance. Heres the issue I am having I have a 1976 Ebko boat with the 165hp mercruiser in it. The motor has been completely rebuilt. I put the boat on the water yesterday and at WOT i am only pushing about 2900 rpms. FRom what i have read i should be pushing about 39-4300rpms. Is this correct? I currently have a 14.5inch prop with a 19 pitch. I have been told if I change the prop that could fix the problem?? What should I change it too and how much difference will it make. Thanks guys I could really use your help.

Ayuh,.... Welcome Aboard,.... Sounds like the drive's ratio is wrong,.... I'm guessin' it ain't the original,..??

You can try a 15" pitch prop,... If that ain't enough, yer gonna need to swap the drive's ratio...

 

[harbolt1]

Re: HELP prop for a 165hp mercruiser

I really couldnt tell you if its original or not. I know next to nothing about boats. Just trying to get some helpful advice, thanks for posting I will try the 15'' pitch prop.

 

[harbolt1]

Re: HELP prop for a 165hp mercruiser

also should I keep the same diameter of prop or should I change that too?

 

[Bondo]

Re: HELP prop for a 165hp mercruiser

also should I keep the same diameter of prop or should I change that too?

Ayuh,.... Forgetabout Diameter, you have little choice in the matter, a Prop Engineer took care of it for ya...

Shop for Pitch, the diameter will just follow along...

As pitch goes Up, diameter, generally, goes down...