TOPIC: Too Much Water in Lower Unit - needing input

1966 Starflite 100.

Been running it quite a bit this summer and looks like it's a keeper, but I'm getting an unacceptable amount of water in the LU - after a day out the oil comes out like yogurt. I've been changing it about every 10 hours of run time but the right solution is to get it sealed up.

Soooo....

The gear case is not leaking any oil while out of the water. I do get water in the oil when running it out of the water with the hose attached so I assume it's coming through the cooling system.

I'll probably tear into it starting in October but I want to get a jump and parts so I can have everything ready when I start.

How do I get this beast sealed up? What parts do I need? I have the parts manual but I have not been able to locate the driveshaft seals.

Upper seal most likely

Pressurizer the LU between 5 and 10 psi and look for an air leak

you can get a seal kit for it at Serria Marine but you will need the mumbers for the kit and I don't have them handy. But someone on here will have it.
Mike aka pathfinderz1

www.marineengine.com/parts/vintage-evinrude-johnson/278787/catalog.html?http://www.marineengine.com/parts/vintage-evinrude-johnson/278787/27878700001.htm

upper seal sierra part #18-0174

Prop seal Sierra part # 18-2012

TallTexan wrote:

Upper seal most likely

Pressurizer the LU between 5 and 10 psi and look for an air leak

How do I do that? I assume you drain the oil and blow some air in the drain.

Do I pull off the lower unit? I suspect that the leak is internal from cooling water given the lack of any oil leaking from the gear case.

How do I detect internal leaks in the cooling system?

What's the story with the sealed shift wires? Is that to keep oil down or water up?

Marine Engine does appear to have most of the seals. I remember now that the grommets around the water tubes to the power head were in rough shape.

With out the right tools you will need a helper

I have an air regulator on the compressor that I set for the pressure that I need. I have a blow gun with a rubber tip

I pull the LU from the motor, pull the pump and housing (if I have a leak I am going to have to do that any way); drain the oil and then have some one there to fill the LU with air (Through the drain hole)and hold blow gun in place to hold the pressure while you look for leaks...I sometime taken a 50/50 mix of Dawn and water as spray the seals and look for bubbles

Once I had to set the LU in a test tank as to see where it was leaking

After all seals are replaces you can do a holding test...get something cold to drink and set up ...fill the LU and cut the air off at the compressor ....you will need to have a gauge in line.....Sit for 10 to 15 mins watching the gauge as to see if it leaks down ...

www.northerntool.com/shop/tools/product_200324799_200324799?cm_ven=natural&cm_cat=netconcepts&cm_pla=Google&cm_ite=air%2Bblower%2Bgun

Remove lower unit

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Hurry to your local boat shop , they will test properly for a minimal charge.

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I use a homemade unit / gauge and bicycle pump to pressurize.

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Technique has not failed me in 40 years !!

Someone on the

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aomci

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classifieds is selling / giving away 2 of those lower units for $50.00

professor wrote:

Someone on the

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aomci

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classifieds is selling / giving away 2 of those lower units for $50.00

Thanks, might look into that.