1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

robfye30

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Jul 28, 2013
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Good day all!
First of all, let me say I am a NOOB at boating. After giving the motor a good once over (carb rebuild, replacing all fuel and vacuum lines, and a few odds and ends here and there) I finally got this boat running. After MANY trips back and forth to the lake, I finally get the thing dialed in where I think it should be. Last weekend I took it out on the river to do some catfishing. When we went out it was late at night so i took it really slow. Therefore I couldn't notice anything wrong. Once morning hit and we were about to change spots, I get it up on the river and it keeps revving out like the prop comes out of the water. it will run fine at about 1800 rpm's but anything past that and it feels like it slips into neutral. NO bangs, pops, or grinding at all. power it back down to about 1800, and it does ok. So I park it. I took the plug out of the top to see if the gearcase was full...nothing. I took the drain plug out to see the condition of the oil...VERY black. BUT!! Before the oil came out, about a cup of water ran out first. Then about MAYBE a cup of oil came out. So I have a leak somewhere. I noticed a small trail on the propeller. Maybe a shaft seal? Weird. I thought if there was water in it, that it would be milky. NO shaving on the drain magnet either. Would it be ok if I were to fill it back up with gear oil and give her another go? Or is this something I need to worry about? Hopefully this is in the right section. I have searched with no luck pertaining to MY problem. Thanks to any and all who respond.
 

Daviet

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

Welcome to the forum.
There are several places where water can get into the lower unit, but it might be something as simple as the gaskets on the drain/vent screws. I would install new gaskets on the screws and fill the lower unit and check it after you run it a bit.
The slipping at 1800 RPM's sounds like a spun prop hub, you might want to check that out also.
 

robfye30

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

Thanks Daviet for the quick response. I didn't think about the spun hub. I need to find a marker or grease pencil. Could it also be because there was little fluid in there? Also, what about the water? Why would water come out but not mix and turn brown? Again...very new to this. sorry for the dumb questions.

Oh! Is the spun prop hub test something I can do without taking it to the lake?
 
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Daviet

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

If you let it set long enough the water and oil will separate and the oil will float on top of the water.
You are going to have to put a load on the prop to check it. You might be able to just back it in the water and run it on the trailer to see if it slips, sometimes that works if the hub is going out.
 

boobie

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

You should have the lower unit pressure and vacuum checked to see exactly where it is leaking.
 

robfye30

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

Sorry for the extreme delay! Working a weird shift and don't have a lot of time for myself. I took the boat to the lake and used a prop my friend had lying around. IT WORKED GREAT! Thanks for all the help on that issue.

Now. I went fishing with it yesterday and it ran wonderfully. When morning came, we took off to another spot and idle around for about 10 minutes. after that, we headed back for hoime. I had it at full speed for almost 20 minutes (about 5 miles). When i got to the ramp I put it in neutral. As soon as I did, an alarm went off. I immediately turned it off as I didn't know what it was. I was able to star *** up again but the alarm was still going off. (had no choice so I could get it on the trailer)
Could it be overheating or something? And why would it last so long before overheating? Wouldn't it have overheated while I was idling for 10 minutes. Could something like this just happen?

Again...Thanks to everyone for the help and different opinions! Greatly appreciated!
 

Daviet

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

A water pump impeller can go out in a matter of seconds. Do you know when the water pump was serviced last?
 

robfye30

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

Unfortunately, I do not. The boat is old and the guy I bought it from was even older. (lol) It was sitting in his yard (he said) for 2 years. so I doubt very strongly it was taken care of.. I'll price some and see if my buddy can help with it. Thanks again for all the help. Hopefully be back on the water this weekend. Got some fishing to do!!
 

Daviet

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

Let us know what you find.
 

iwombat

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

You've got to take the lower unit off to service the water pump. Might as well have it pressure tested while it's off.
 

boobie

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

If you have it pressure tested you'll know exactly where it's leaking. No guess work.
 

kahuna123

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Re: 1973 Evinrude 85393M 85hp Outboard Leaking water in gearcase?

Congrats on having one the runs. Mine is a PITA
 
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