Mercuriser I/O hub size

[81 Checkmate]

Looking for a used prop for the pontoon.... 2001 - Mercrusier 3.0 I/O, Alpha 1 - It has a 4 Blade Alum 19" pitch on it now. Not sure what the dia is.... The numbers - 20 mph @ 3400 RPM WOT

Found a stainless prop on Craigslist today......13-1/4" x 21" for $20 bucks... The guy said the center hub is missing.
I cant tell from the pictures if it will fit..... Looks like a mercrusier prop. He said the inner hub hole measures 2 -1/4"
It's all the info i have.

He is over 3 hrs away from the house...so im going to drive to look at it. If i think it will work im going to send him a check and he can ship it to me.

Do you think this will work?

 

[jestor68]

Re: Mercuriser I/O hub size

If the 19 only gets 3700rpm, the 21 won't be any better; probably worse.

You need 4400-4800 rpm, which means less pitch, not more pitch.

Get a Solas Rubex 15 X 15.

Besides, that diameter sounds too small; more like a prop for a 115/125 Mercury outboard(4.25" gear case). Your Mercruiser has a 4.75" gear case. I'm 99.9% sure that's the wrong prop for your Mercruiser. Don't waste time looking at it.

 

[81 Checkmate]

Re: Mercuriser I/O hub size

I miss spelled....I am not going to get to see it in person. Way to much gas for a $20 prop

Got side tracked, And I didnt ask my 2nd question......does anyone know what the inner hub hole size is on a prop for an Alpha 1
If it will fit my hub...I was going to try it on the Checkmate also....MC-1 Drive should be the same as Alpha 1

 

[Chris1956]

Re: Mercuriser I/O hub size

Mercuriser Alpha I use a 4-3/8" prop hub. They have a 15 spline propshaft.

 

[SkiDad]

Re: Mercuriser I/O hub size

i would definitely go at least 15 pitch or maybe even 13 on a pontoon. Just my humble opinion

PS - that outdrive is so popular that you could probably find a bunch of used ones at your local marine store for say 50 or 60 bucks.

 

[jestor68]

Re: Mercuriser I/O hub size

Mercuriser Alpha I use a 4-3/8" prop hub. They have a 15 spline propshaft.

You need to visit the prop section(that's the easy and quick source). What is the hub size for a Mercruiser Alpha 1? Mercury Marine says it's 14.75". You must have a better source.

 

[Chris1956]

Re: Mercuriser I/O hub size

Jestor, The small merc gearcases are listed as 4-1/4. The larger gearcases (V6 OBs and Mercruisers) are 4-3/4. My mistake.