Mercruiser Alpha One Gen II ---PROP Question

[castik]

Hey guys,

I have a question; It's time to replace my prop and now I have talked to two local people but they do not know which one is better. My choice is between:

1. PART # IS 48-79674 - 14.5 X 19 PITCH, 15 SPLINE, ALUMINUM

2. Part # 48-13701A41, Designed for the PORT SIDE ( don't know what that means), 15 ? inch Diameter , 19 inch pitch, STEEL (Mercury Quicksilver Mirage Stainless Steel-Port Side Propeller)



I have a 1996 Bayliner Capri with an Alpha One Gen II engine. I'm not sure what my prop is...if its 14.5 or 15 inches!?


Cheers!

 

[Haut Medoc]

Re: Mercruiser Alpha One Gen II ---PROP Question

It should say on it what the size is....
Look harder......
You are gonna want an RH if it is a single screw.....
I'm thinking they mean LH when they are saying port....​

 

[tommays]

Re: Mercruiser Alpha One Gen II ---PROP Question

you need to post in the prop forum


Watch out for that PORT PROP it sounds like a LEFT hand prop and all standard singel screw alpha drives use right hand props


Tommays

 

[Dryon]

Re: Mercruiser Alpha One Gen II ---PROP Question

First you need to know your gear housing rotation.
Second you need to know your RPM's at WOT.

 

[castik]

Re: Mercruiser Alpha One Gen II ---PROP Question

you need to post in the prop forum


Watch out for that PORT PROP it sounds like a LEFT hand prop and all standard singel screw alpha drives use right hand props


Tommays

Can you pleaes move it for me please.



My boat is at the local marina and I cannot look on the prop itself!

 

[Haut Medoc]

Re: Mercruiser Alpha One Gen II ---PROP Question

You should post your engine size.....

 

[Bondo]

Re: Mercruiser Alpha One Gen II ---PROP Question

My boat is at the local marina and I cannot look on the prop itself!

Ayuh,........

If you Can't find out What prop is on the boat Now,..........

You really Can't buy a new copy of your Prop,.....
Muchless decide whether Any prop might possibly work properly On your boat........

 

[castik]

Re: Mercruiser Alpha One Gen II ---PROP Question

you need to post in the prop forum


Watch out for that PORT PROP it sounds like a LEFT hand prop and all standard singel screw alpha drives use right hand props


Tommays

I have called the marina and they told me that I should go with the 14.5" ...but I don't think they personally know my boat. It was a just lady working at the front desk.

 

[Don S]

Re: Mercruiser Alpha One Gen II ---PROP Question

Moving this over to the Prop Questions and Topics forum.

 

[castik]

Re: Mercruiser Alpha One Gen II ---PROP Question

I think is 5.7L.

 

[stevens]

Re: Mercruiser Alpha One Gen II ---PROP Question

What an exasperating thread! ....Don't know the engine, don't know the prop, can't get to the boat, lady at the front desk says, locals don't know, and starting off by choosing between a left and a right hand prop?

Do yourself a favour; wait until the boat is due back on water. Find out what engine and drive you have and which way the prop rotates. Find out what the current prop is (part number or type & size, i.e both pitch and diameter). Measure the current performance, i.e. RPMs at full speed ahead (=WOT=Wide Open Throttle).

Then! post back here so that the guys can give you some meaningful help.

(...and sorry if I come across as a grump... just hard to help without any of the facts available)

 

[castik]

Re: Mercruiser Alpha One Gen II ---PROP Question

I just picked up my boat from the marina and I have measured the prop. It's around 13(or just a bit more) inches but I have thalked to the guy that it's supposed to sell me the 14.5 aluminum prop and he siad that 14.5" is standard for an Alpha One engine. I personally think that it would fit but not 100% sure since this one its 14.5".

 

[John_S]

Re: Mercruiser Alpha One Gen II ---PROP Question

The diameter is only part of the equation. A 14" diameter range prop (14, 14.25, 14.5) on capri/alpha is a pretty safe bet, it is the pitch that will make the major difference. If you select a pitch that is too large for your boat/engine combination, you will lug the engine and stand a good chance of pre-mature engine failure.

Either, do as Stevens says, or call your current boat performance good, and find exact replacement for what is on there. This is risky, given you don't know what the previous owner did. If you look at the end of the prop, around the prop nut, you should find a part number. Also, if you look closely on the main body of the prop, the size is usually stamped in it.

Also, if you look on the Bayliner website and find the parts manual for your boat, it will usually have the different engine/drive pkgs, along with standard prop. Again risky, because you should prop for your typical load and conditions, not the "general" one.

My advice is do a Stevens says. Wait to next year, and test and see what your current wot rpms is, and then post back.

 

[Bondo]

Re: Mercruiser Alpha One Gen II ---PROP Question

There are #s stamped onto the Prop,...... you Need those #s.......

Again,........ Just Guessing,.. Will get you No Where.......

 

[Hashi]

Re: Mercruiser Alpha One Gen II ---PROP Question

Dude! Start reading these all of these threads before asking. You can get a lot of useful information from these professionals. They're there to help us and keep boating a safe and enjoyable. For instance, I've learned to keep different size props for different loads and type of use for that day. If I plan to go out with four people or more (heavy load), I'll use a smaller pitch. But, if its just me and the wife then, I use the higher pitch to get the RPM's I want. I also read that diameter doesn't really matter. But do what the other posts said about getting the number stamp from somewhere on the prop.