New prop floats on prop shaft and has some play

[Westieman]

Hello boaters!
I recently acquired a small boat with a very nice Mariner 50hp 3 cylinder.
It is a 1995 Belgian build engine with some 112 hours on the clock.
As can be seen on the pic., the lower part was once replaced as was the prop.
I noticed that the prop has some play on the prop shaft and floats back and forward by a few mm's.
The forward and backward trust hub seem new as well.
The number found on the Hubs are 8m0042293 and 835248.
The number on the prop is 73136A45.
I noticed that for some outboards there is a adapter kit available.
View attachment VID_20210704_165517228.mp4


Could anyone tell what is wrong here please?
It all seems new but I can not believe that this is how it should be.
So thank you all for your ideas or suggestions!
Greetings from Flanders!

 

[Sea Rider]

Once the hardware and nut are fully torqued in on the prop shaft, there's always a small play back and forth when pushing in/pulling out the prop which it's normal if that's the prop shaft play you're worried about ?

Happy Boating​

 

[Westieman]

Once the hardware and nut are fully torqued in on the prop shaft, there's always a small play back and forth when pushing in/pulling out the prop which it's normal if that's the prop shaft play you're worried about ?

Happy Boating​

Thanks for the reply!
The prop shaft has no play at all. There is only some play of the prop on the shaft. I was comparing with the original prop on the same shaft. There is no play with the old but OE prop. The old prop is warped and touches the housing. There are some scoring marks on the old prop.
I think the previous owner hit something or maybe he forgot to raise the outboard while moving around. The old housing, came with the boat, has a slight damage to lower fin.
So, someone replaced the lower housing and the prop. Just wondering if they maybe ordered the wrong parts.
It is the first time I notice so much play on a prop/ shaft. Other Evinrude's and Mercury's never had this. Is this maybe a special prop that needs the play?

 

[QBhoy]

I think you have the wrong hub kit or at the least..thrust washer. Or perhaps the hub isn’t pushed all the way home yet. Is the nut tight enough ?

 

[Westieman]

That must be the problem, wrong hub kit. The nut is fully tightened. I noticed that for the black max props there is a different hub kit available to go on the older outboards. I guess they ordered the prop without the kit and just did not look any further or someone messed with the parts ( all the reference numbers on the box are striked out )

In the meantime I put the original prop back on with the original thrust washer. There is no play at all. In fact, I will leave it on. It is in as new condition. That solves the problem and, more important, gets the boat back on water!
Thanks for the info QBhoy !

 

[Cortes100]

Another thing to consider, you may very well have the wrong hub kit. Merc has these reflex hubs that are designed to move a fair bit back and forth on the prop shaft. They have little fingers as pictured below.
When I got my new 4 stroke outboard, I thought my prop was not installed properly only to find it had this new funky hub assembly.

 

[Westieman]

That looks weird! Is the hub pressed in? I will have a closer look on the hub tomorrow. Anyway, there was play in all directions and that I think is unacceptable. The prop even touches the lower housing. Will keep you posted.
Thank you for the info!

 

[Texasmark]

I agree. You have slop both in the lateral (when you grab a blade tip) and longitude (when you push it back and forth) and shouldn't have either. Do not run the engine like that!

Any numbers on the prop...either end or on the barrel? If you could identify the prop it would help.

Your thrust washer is splined.....thrust washers "are not"splined as they have a sloping cylindrical ID to fit the sloping prop shaft at that point and the reason for sloping is that the prop is bolted up against the thrust washer with something like 50 ft-lbs of torque so that it doesn't flop around on the prop shaft. The idea is to perfectly center the front of the prop and the wedge is to have a centered surface to support the front of the prop allowing for something to push against when applying the nut torque. The prop shaft does move in and out about 1/8 to 1/4" if you push hard enough ...once you get the right thrust washer and hub and get it torqued....the prop and shaft move in unison...no slop between prop and prop shaft. That in and out movement is the "over run" clutch in the LU gear box and is part of the design for when the engine decelerates while in F gear. That's one of the checks you make before you run the prop....push in and while pushed in, ensure that you can rotate the prop without it touching the LU housing.

So, let's start by checking the prop all over for some numbers.

Another thing to consider, you may very well have the wrong hub kit. Merc has these reflex hubs that are designed to move a fair bit back and forth on the prop shaft. They have little fingers as pictured below.
When I got my new 4 stroke outboard, I thought my prop was not installed properly only to find it had this new funky hub assembly.

View attachment 345649

I'd verify what you said about those hubs. What is the installation torque on those "funky" hubs? Considering pressed and removable hubs other than this type are torqued to about 50 ft-lbs on engines this size to prevent movement against the prop shaft. Makes no sense!

I think you have the wrong hub kit or at the least..thrust washer. Or perhaps the hub isn’t pushed all the way home yet. Is the nut tight enough ?

 

[Westieman]

I agree. You have slop both in the lateral (when you grab a blade tip) and longitude (when you push it back and forth) and shouldn't have either. Do not run the engine like that!

Any numbers on the prop...either end or on the barrel? If you could identify the prop it would help.

Your thrust washer is splined.....thrust washers "are not"splined as they have a sloping cylindrical ID to fit the sloping prop shaft at that point and the reason for sloping is that the prop is bolted up against the thrust washer with something like 50 ft-lbs of torque so that it doesn't flop around on the prop shaft. The idea is to perfectly center the front of the prop and the wedge is to have a centered surface to support the front of the prop allowing for something to push against when applying the nut torque. The prop shaft does move in and out about 1/8 to 1/4" if you push hard enough ...once you get the right thrust washer and hub and get it torqued....the prop and shaft move in unison...no slop between prop and prop shaft. That in and out movement is the "over run" clutch in the LU gear box and is part of the design for when the engine decelerates while in F gear. That's one of the checks you make before you run the prop....push in and while pushed in, ensure that you can rotate the prop without it touching the LU housing.

So, let's start by checking the prop all over for some numbers.

I'd verify what you said about those hubs. What is the installation torque on those "funky" hubs? Considering pressed and removable hubs other than this type are torqued to about 50 ft-lbs on engines this size to prevent movement against the prop shaft. Makes no sense!

I mentioned all the numbers I could find at the beginning of this thread.
The only number I can ad is the number found on the original prop:
48 73136 A40 13P. Still wondering why they replaced in first place?

 

[Texasmark]

Amazon.com: Max Motosports Aluminum Propeller fit Mercury 25-70HP 48-73136A40 10-3/8x13 Pitch RH : Sports & Outdoors

Buy Max Motosports Aluminum Propeller fit Mercury 25-70HP 48-73136A40 10-3/8x13 Pitch RH: Propellers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Well it says it fits your engine and has the hub kit included. Maybe there is a hub kit mix-up with this one and the current prop? Still have to answer the question as to the thrust washer...was it in the/with the hub kit like is the case with some/most iboats props?

 

[Westieman]

Amazon.com: Max Motosports Aluminum Propeller fit Mercury 25-70HP 48-73136A40 10-3/8x13 Pitch RH : Sports & Outdoors

Buy Max Motosports Aluminum Propeller fit Mercury 25-70HP 48-73136A40 10-3/8x13 Pitch RH: Propellers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Well it says it fits your engine and has the hub kit included. Maybe there is a hub kit mix-up with this one and the current prop? Still have to answer the question as to the thrust washer...was it in the/with the hub kit like is the case with some/most iboats props?

I have no idea. The new prop was on the outboard when I bought the boat. The "old" prop came with the boat in the box you see on the previous picture. There was a little bag with the old washer.
The first pictures show the washers that I found on the new prop after I took it off.
There might be a mix up somewhere, but that is the reason of this thread.
Something is wrong but what?
Thanks for the info!