Prop choice for a 2001 40hp Nissan

[Reelgator]

I have a 40hp Nissan on a Gheenoe Classic. My top end is horrible (27mph).

I am wanting to get a new prop and have been told I need to go to a 10 1/8th x 15 pitch.

I am a prop idiot, would this prop setup work well?

 

[rogerwa]

Re: Prop choice for a 2001 40hp Nissan

Need to know your WOT RPM and current prop pitch to really provide any advice.

You need to adjust your prop so your WOT RPM is in the 4500-5500 RPM range. i would recommend trying ot aim for the higher end of that range.

If you can provide the RPM and currnet pitch we can calculate the proper pitch assuming the slippage remains constant and the speed you report is accurate (GPS vs pitot tube speedo).

 

[Reelgator]

Re: Prop choice for a 2001 40hp Nissan

Ok, have some numbers.

I put on a 11.1x14 prop.

WOT RPM's 3800. Max per OM is 5800rpm.

Top end is same as with a 25hp on the boat.

Per GPS 27 mph.

I am confused.......

 

[TOHATSU GURU]

Re: Prop choice for a 2001 40hp Nissan

With the numbers provided, you would need something around an 11 pitch. But, your intial numbers sound wrong. Are you using a Nissan/Tohatsu tach?