1984 Evinrude 25hp prop size

[justjohnl]

Evening. I’ve picked up a 1984 evinrude 25hp with pull start for a boat project however it didn’t come with the propeller. First time buying a new propeller and it seems to be a bit of a minefield as to what size and whether or not it would fit the shaft. Any help would be greatly appreciated.
Thanks

John

 

[racerone]

It depends on what boat the motor is pushing.----You need a splined prop and one that does not have through the prop exhaust.------Post part # of some props that you are looking at.

 

[jimmbo]

20-25 spline drive are the choices, with OMC's slightly optimistic projections of boat sizes and speeds. I always found going to the next smallest from their Recommended to be more suitable

 

[FunInDuhSun]

I have a ‘85 ‘rude 25HP and use a 10 x 13 prop. It is 14 spline.

 

[racerone]

???----But the 85 model 25 HP appears to have a totally different gearcase !!

 

[jimmbo]

They switched to the 35 gearcase that early? Oh well, the chart for the 35 thru hub will be fairly close

 

[racerone]

The 84 model 25 has the older split gearcase.-----The 85 model 25 has the through hub exhaust according to parts book.

 

[jimmbo]

Thanks for the correction.

 

[justjohnl]

Thank you for the replies.

Trouble I’m having is finding something to fit the prop shaft (14.5mm diameter) . I presumed that they would be all standard as a prop I took off a ‘94 evinrude 30 was much bigger.

 

[jimmbo]

Interesting. Can you post pictures of the motor and the Prop?

 

[justjohnl]

Interesting. Can you post pictures of the motor and the Prop?

 

[racerone]

The prop in the 4th picture is a " through the hub " and totally wrong for your motor.-----Where are you looking for a prop ??----This should not be difficult in my opinion.

 

[racerone]

And a prop attaches to a motor but----FITS ----the boat.-----What size boat do you have.

 

[jimmbo]

Are you certain about the Year of the Engine?

 

[jimmbo]

The prop in the 4th picture is a " through the hub " and totally wrong for your motor.-----Where are you looking for a prop ??----This should not be difficult in my opinion.

Don't look like a Thru Hub as implied in Post #7.

 

[justjohnl]

Are you certain about the Year of the Engine?

That’s the model number. Looked online and it said it was an ‘84. The boat it’s going on is a 20ft Norman conquest. It’s my first boat and first time looking into prop sizes etc.

 

[racerone]

Not sure why this is so confusing to the OP ??-----The prop in picture #4 simply will not fit on an 84 model !----And you have an 84 model.----Your location ?

 

[justjohnl]

Not sure why this is so confusing to the OP ??-----The prop in picture #4 simply will not fit on an 84 model !

Yes I’m aware it won’t fit, was trying to show the difference in size. Hence why I’m asking for help in find the correct sized prop

 

[racerone]

A 9X9 ----3 blade -----13 tooth spline----For NON through hub exhaust.----0763585----First # is for 9" diameter second # is for 9" pitch.----And on a 20' boat you might need a 7 or 8" pitch.

 

[jimmbo]

Not sure why this is so confusing to the OP ??-----The prop in picture #4 simply will not fit on an 84 model !----And you have an 84 model.----Your location ?

The thread got a little derailed, for me at least, when a 3rd Party piped in with having an 85. You were pointing out that the 85 used a Thru Hub. I figured it was the OP having an 85.