1979 90 hp merc prop pitch??

[woffie27]

hi, I have a 1979 90 hp merc outboard engine and I also have a 16 to 17 foot boat. I was wondering if any one could help me out with the prop size, pitch, diameter. etc.

 

[woffie27]

1979 90 hp merc prop pitch??

also, the wot (wide open throttle) in the merc book is 4500-5000 rpm. so I am wondering what pitch\diameter I would need with a 16 foot boat and a 90 hp merc engine?
thanks all for the help.

 

[Bondo]

Re: 1979 90 hp merc prop pitch??

Until you go out,+ Run it to establish a Benchmark of the WOT rpms, with Whatever pitch you Have..........

Everything will just be Guesses............

Btw,.... I might be Wrong,....
But,.... 4500/5000rpms sounds Very Low for a 2-stroker.......

 

[jimmbo]

Re: 1979 90 hp merc prop pitch??

4500 to 5000 is what merc speced for the 90hp inline 6. A 15" or 17" pitch should be in the ball park

 

[Napps11]

Re: 1979 90 hp merc prop pitch??

I am curious as well. I have a 1979 90hp merc on my Swiftsure Power Squadron (which is the exact same boat at Glastron cvx-16). I am running a 17p aluminum prop. I got 42 MPH at 5000RPM. I get out of the hole extremely fast. Any recomendations as for pitch props for me to go faster? what is the WOT on a 1979 90HP Merc? Recomendations for stainless and aluminum props would be greatly appreciated!

P.S. What would the differences for a 3 vs. 4 blade props?

Thanks!