omc prop questions

[james69]

I have a 1986 fabuglas. I bought the boat used and have no info on motor size etc. I know it is an omc 4 cyl with a cobra sterndrive. My quetion is how do i find out what is the best prop size to buy. I am currently running a 13x19 aluminum 3 blade but when i accelerate with any weight in the boat it is extremely slow to get on plane. I dont plan on skiing with the boat but i do want to have a lot better takeoff without sacrificing too much top end. Any help will be greatly appreciated.

 

[steelespike]

Re: omc prop questions

Please check the stickies at the top of the page.Get us as much info as possible.
Your probably pretty close to the top in prop size for most speed .
Not good for hole shot.You could try trim tabs ;something like smart tabs
are easy to install and effective. Also could try a vented prop.
These would help maintain top end while improving hole shot.
The simple way out is to try a 17" pitch. This will improve hole shot but you will have to watch the rpm(about 4,600). and may lose some top end.

 

[james69]

Re: omc prop questions

Thanks for info i'll try that and see what happens. Ido apologize for not having more info i there is no info on or around this motor and i dont know how to go about finding any out.

 

[junior1113]

Re: omc prop questions

what are current wot rpms??

 

[james69]

Re: omc prop questions

To be honest i havent noticed. The few times i've taken the boat out my family's been with me and i get told to slow down that i'm going too fast. I do know that with my wife and daughter in the boat i've had it to 30if that helps any at all.I will be sure to check when i take it out again.

 

[james69]

Re: omc prop questions

The wot rpm seems to be about 3800