Lower End Water in Oil/Bad Prop?

1gabby

Cadet
Joined
Jan 7, 2009
Messages
16
Good Morning,
I have a 1985 or 6 25 hp. Johnson that runs like a clock.
When draining the lower end at the end of last season I had water in the oil, at least it appeared to have water in the oil.
Instead of pulling apart myself I decided to take it to my local Johnson/Honda dealer and let them take care of it.
I haven't had the time to work on it and figured they were more experianced and if they found anything else wrong they would be best to fix the problem.
After they leak checked (receipt says 20 min. @ 15 psi in vacumn and under press.) they said the press./vacumn test says there are no leaks.
They put a dial indicator on the prop shaft and it ran true.
They are claiming that due to the condition of the prop (typical wear running the shallow bays I run in) that there must be a vibration/out of balance in the prop that is causing the water to get into the oil.
I would think the seals could make up this differance.
FYI-While running the boat I have not noticed an unusual vibration-but when I get a chance to run on new prop I might see the differance.

What's you thoughts on this theroy of how the water got into the oil?

Mean while at their shop I did buy a new Johnson prop.
I noticed that the new prop has a cup in the blades.
It feels like my old one doesn't.

How much differance will the cup make?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,465
Re: Lower End Water in Oil/Bad Prop?

What's you thoughts on this theroy of how the water got into the oil?

Ayuh,... Makes perfect sense...
How much differance will the cup make?
Try it,+ you'll know...
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Lower End Water in Oil/Bad Prop?

I don't remember the exact figures cup adds pitch maybe an inch or 2.
It may lower your rpm could change your hole shot for the worse.
When changing props and style the results become clouded in an allready somewhat unpredictable endeaver.If it makes your motor lug it could cause premature repair problems.Of course going from a beatup prop to new adds another variable.Perhaps the dealer will let you test the prop and make a selection based on the results. You should get max rpm and speed readings to do it right.
 
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