which replacement prop do i need?

ed_dash · 28 March 2010, 13:28

Hi

I am away from the boat so cant check and looking at replacement props. I have 60hp Mariner 2 stroke from 1997, currently running a 15"P but im a bit confused by looking at replacements. I was looking at one on ebay (no. 360213763332) but it doesnt say the number of spines. Some i have seen have 13 and others have 15.

As i dont want to buy the wrong one i was curious if anyone on here knew the number of spines for that engine, diameter of a standard mercury/mariner 15"P prop and the size of the gearcase i think its either 3 1/2" or 4 1/4"? I am tending towards the 4 1/4" but not 100% sure.

I think my plan is to buy either a new or refurb'd one, same size and then get mine refurb'd as a spare, sound good?

Many thanks

9D280 · 30 March 2010, 08:50

Ed,
For what it's worth, my old Yam 55 and the current Merc both have 13 spline shafts. (as both supplid to Mariner, I guess you will also have a 13 spline. I gess the 15 spline ones are OMC or another make.

I tried last night & the old Yam prop drops straight onto the Merc Shaft / gearcase. Having said that, the thrust / locking arrangements are differnet, so although it "fits" it's niot a simple swap.

If you got the engione size, dive onto any prop website, they usually have charts showing splines & diameters etc. The O/D of the prop will depend on what you want to do. Bigger diameter = more grip, but less RPM, smaller = more RPM (so higher pitch & speed) but with less grip so it "lets go" more easily.

If it works with your current prop, rattle the PN down the phne to your dealer & they should be able to replace or suggest an equivalent.

Downhilldai · 30 March 2010, 12:29

'97 Mariner/Merc 60 should have a 3 1/2" gearcase. The 'Bigfoot' motors have the larger 4 1/4" gearcase and a lower ratio gearset.

ed_dash · 30 March 2010, 13:05

thanks for the advice, i think what has confused me the most was the steel developments website, for the 3 1/2" gearcase their props for mariner/mercury go 14"P & 16"P and not 15"P but are using 13 spines. Where as the 4 1/4" gearcase does have a 15"P but uses 15 spines.

I think it may just be a case of waiting till i get home, and take one off, then see exactly what is written on it and count the spines if necessary.

phillnjack · 09 April 2010, 18:14

what sort of boat are you using the engine on and what type of things do you use it for ?

if its speed you want then go for a bigger pitch prop and drill vent holes in it.
if its for water sking or towing ringo's go to 11 or 13 inch pitch.

I was using a 13 inch and got good hole shot, then put on a 15 that just wouldnt get up any good for ages.
Drilled a couple of vent holes and it went like the clappers and then gave good top end.

Fuel economy also was better once up on the plane.

ive got one in my garage, shame your not closer you could of given it a go and see for yourself.

A couple of mates thiought i was mad drilling the prop, untill they saw the results for
themselfs.
Soon had them convinced ha ha

ill take a few pics of it tommorow.

phill

ed_dash · 09 April 2010, 22:39

that sounds like a weird idea but id like to see pics of how you drilled them.

All i wanted to know if anyone knew what prop i needed for a 60hp Mariner 2 stroke. I have a 15 that is fine for what i do and was looking for another 15 P but i saw a few diff types. some with 13 spines others with 15 and diff size gear cases.

I am home now, ordered a refurb'd 15 P with 3 1/2" gearcase and 13 spines. think i will get the old one refurb'd and keep as a sapre.

phillnjack · 10 April 2010, 08:47

If you look at the large stainless props used on the big outboards, youl see that many of them have vented props.
The idea is that at pull away the exhaust gases go through some of the vents and help spin up the prop.
Once the prop gets going the exhaust then goes through the hub as usual.

It realy does work.

On Dell quay dory 15 sportsman with 4 on board it was struggling like mad to get on the plane with a certain prop.
I then drilled the vent holes and it just lept onto the plane.

I will go down to garage in a while and take pics of the prop for you.

sorry to have gone off topic, but it will help you in the long run if you decide to go for
more performance from the engine.

phill

Mark J · 10 April 2010, 09:26

There is a good description of how it works here:
http://www.marinemechanic.com/site/page76.html
Mark

phillnjack · 10 April 2010, 10:22

The results for this are amazing.
I was very worried about destroying a good propellor when i first heard about it.

But now im always ready to get out the drill ha ha

If you want a boat that has good top end but just not enough to pull the toys up quick, then this can be a good reason for drilling.

It turns a decent prop into a brilliant prop.

Thanks for the link, i had forgotten about that one ha ha

phill