25 hp prop

[mattyv]

hey guys,

where could i get a different pitch than stock prop for my 1975 25 hp evinrude? i have the motor on my saturn inflatable and it has plenty of bottom end but really screams at the top since it is such a light boat. i know i can get some more mph out of it with a more aggressive prop. thanks in advance

 

[mattyv]

Re: 25 hp prop

oh wait i think i just found a place....does anyone know the stock pitch?

 

[K.P.]

Re: 25 hp prop

There is no such thing as "Stock Pitch". The size of the the prop is stamped somewhere on the prop or the model number is which will lead you to the prop pitch.

 

[BF]

Re: 25 hp prop

not 100% sure, but I think the "standard" pitch would be 10"... I recently replaced my 25 hp 'rude, but I had a 9" on it pushing a 16' aluminum utility boat... handled a load well. I also had an for 11" on it, but anything except an empty boat and it was slower than with the 9". 10" might have been the best of both worlds, but not what I had.

So, if your rig is really light, MAYBE an 11" would be right. Yes, you should check what pitch your current prop is... maybe it's an 8 or 9" in which case maybe you would want to try a 10".

good luck

 

[mattyv]

Re: 25 hp prop

ok i pulled the number off the prop: 012013 which according to iboats is already an 11 pitch

http://www.boat-props.com/propeller..._id=30&**********=702277269&*******=937262891

anyone know where i can get something higher?

the boat has plenty of acceleration and gets out of the hole quick even with three people (prob around 450 lbs) dry weight of the boat is only like 150 lbs. rough calculations....the whole set up with three people, engine, gas etc is about 750 lbs

 

[mattyv]

Re: 25 hp prop

i found a 12" online but they want 114$ for it....how much of a difference should i get?

 

[jimmbo]

Re: 25 hp prop

Roughly same top speed with poorer acceleration and lower rpm @ WOT

 

[steelespike]

Re: 25 hp prop

You shouldn't make any prop changes without a tach.You could shorten the life of the motor,waste fuel etc.A tiny tach is reasonable,easy to install and fits any 2 cyl. 2 stroke without regard to stator poles.Guessing rpm by sound could be motor suicide.