Need to identify a prop

[bonz_d]

I picked up a used prop recently for my new/used 1975 50hp Johnson. I was told it came off a 1999 50hp Evinrude 2 stroke. When I finally was able to test fit it I found it does not fit. There are no markings on it other than the size and and a S1500 cast into it. It will slide onto the shaft but does not go all the way on. There is about a 1/2" gap between the prop and the gearcase.

Didn't want to put a lot of money into a test prop which is why I bought a used one as there was no prop on the engine when I bought it. My intention was to see how the engine ran before spending the money on a new prop.

Think a prop shop would be able to ID it if I took it in to one? This prop is straight and looks barely used.

 

[steelespike]

Re: Need to identify a prop

Is the old thrust
washer still stuck to the prop?
Size numbers usually appear under the prop nut.
Size might give a clue.
A prop shop can probably identify the prop.
Prop chart says props 1975 to 2005 small gear case are the same.

 

[bonz_d]

Re: Need to identify a prop

There is a thrust washer but the prop will not even go back that far as to seat against it. Size number are on a blade and not the hub. I even looked through BRP site and I'm beginning to believe this wasn't a 50hp 2 stroke. Size is right at 11.25X15

 

[steelespike]

Re: Need to identify a prop

It does seem to be a typical size though diameter seems a little small for a 15" .
Most 15" here are 12" or so.Usually as pitch goes up diameter goes down

 

[bonz_d]

Re: Need to identify a prop

So I was able to take it in to a shop yesterday and the guy told me right away that this is for a Evinrude or Susuki 40-50hp 4 stroke engine. He didn't have to look that long either.

So now I have to see if I can get rid of these and the hunt's back on for another one.

 

[steelespike]

Re: Need to identify a prop

Now that you know what it fits it should be fairly easy to sell.
Maybe your prop guy will let you try some props with the understanding you will by one.
this usually requires a sizable deposit.
I can tell you my 88 50 on a bare 18ft utility with an all up weight of 900 lbs runs a 19" pitch.
Pushes weight really well and pulls a skier pretty good though probably a 17 would be better for beefier skiers.

 

[steelespike]

Re: Need to identify a prop

Now that you know what it fits it should be fairly easy to sell.
Maybe your prop guy will let you try some props with the understanding you will by one.
this usually requires a sizable deposit.
I can tell you my 88 50 on a bare 18ft utility with an all up weight of 900 lbs runs a 19" pitch.
Pushes weight really well and pulls a skier pretty good though probably a 17 would be better for beefier skiers.
I checked props here Evinrude 50 4 stroke 99 - newer and Suzuki 4 stroke 99-2010 and 2011 newer the numbers are the same.
Apparently Suzuki was making motors for Evinrude for awhile.
I imagine the Evinrude 4 stroke is as scarce as hens teeth.

 

[bonz_d]

Re: Need to identify a prop

Hopefully I don't have a problem finding a buyer for these. The prop guy did try to jokingly give me a rash about buying used from the internet. Unfortunately he doen't have any in the shop right now for the 50hp OMC.

That is correct from what he told me that Suzuki made the Evinrude for a few years. I to am thinking this engine may be a rare bird, even in this well populated boating area.

This 50hp is on a 1988 Alumacraft Classic 16 with dry weight stated at 560lbs. dry w/o engine, engine at 200lbs plus gas, 2 batteries and trolling motor, I'm thinking around 1100lbs with me in it. At this weight it had been suggested in this forum to start at a 15 pitch in which I was originally thinking a 17 pitch. This 50hp when I tested it showed 150lbs compression on both cylinders so I'm thinking it should run strong. Then you say you're running a 19 pitch on a boat that's only about 200lbs lighter. Do I need to rethink my needs for this?

 

[Silvertip]

Re: Need to identify a prop

If you go to just about any boat dealer they generally have a pile of used props. You are looking for a 12-1/4 x 15 which is a pretty standard prop for that engine but it depends on what size boat and load it has to push. A common 15 - 17 foot aluminum fishing boat would be happy with that prop. As pitch goes up diameter comes down a bit and vice versa. A 17P prop would likely be 11-3/4 diameter. A 13P would likely be 12-3/4. I"ve used them all and on the JohnyRude 40/50 engines almost always settled with the 12-1/4 x 15P.

 

[bonz_d]

Re: Need to identify a prop

Thanks Silvertip. I have taken that class and understand the principals. On my 35hp I've run an 11X9, a 10.5X11 and now using a SS on it that was a 10.5X11 and is now closer to a 10.2X11 and with that it runs excellant.

The question I have/had in another thread was for a starting point as this 50hp did not come with the boat or with a prop. I'd already figured that a 19 would be too big and a 13 would be too small. While also noticing that the 15 pitch props come in like 4 different diameters between OMC, Solas and Michigan Wheel.

 

[steelespike]

Re: Need to identify a prop

I double checked.Pretty sure the bare boat is about 375 200 for the motor 200 for me 1 battery 40 lbs,
6 gallons of gas 36lbs, oars,anchor,pfds 30lbs 881 lbs. It's a welded hull but for the seat bases and 3 keels.
So a relatively smooth bottom.
Your 16 probably has a slightly smaller footprint so may drag a little with the extra weight,though it does seem a 17" might work.

 

[bonz_d]

Re: Need to identify a prop

Thanks guys for all the input. Guess I'll stick with a 15 to start then tach it and go from there. Now to work on relieving myself of these 2 useless props.