# Evinrude oil leak



## Playin' Hooky (Aug 29, 2002)

Need some help on this one. 1978 Evinrude 9.9hp. Oil/water mix after use, otherwise black oil (post combustion product?) is leaking from a small (drain) hole on the left side of the lower unit just above and forward to the prop shaft "cone". Certified technician said that lower unit/shaft seal isn't leaking, but I have the spots in my driveway to prove that something is otherwise.

Any ideas? 

Thanks, 

Eric


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## STEINFISHSKI (Jan 30, 2001)

I usually get a small amount of post combustion oil that "drops" from the carbs when I tilt my motor. It usually drains out underneath the motor cover, and out the drain holes, and down my motor shaft. If I do not tilt, it will come out the exhaust hub near the prop. It is black, and very smoky to the smell.

My lower unit oil is carmel colored and changed twice a year.


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## davesdecoys (Oct 2, 2004)

Just happened to stumble onto this thread. I have the same problem with my 8HP 93-Johnson. Black oily substance leaks out my exhaust hub near the bottom by the prop & also leaks through the little holes on the lower unit you've described. So is it concluded that this Black oily substance is left over from the 50:1 oil/gas mixture? It sure seems like I have alot of this stuff leaking out-about 1/4 cup? Dave's Decoy Shop


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## steve ypsi (Nov 24, 2002)

I just put a impeller in a 6 merc, while I had the lower unit off I saw that hole and always wondered what it was, well in that Merc it is to drain water out of that area and it was almost blocked, I took a screw driver and got the old dirt and rust out from the top and it still wouldn't drain, I opened up that little hole a fraction bigger with a drill and ran a Stiff wire up there and finaly got it to run the water out fast, I would guess you are holding the exaust gas's which are oily and they accumulate in that area draining out slowly over a day or so, if it was clear and open it would drain while you were running the motor, you never see a newer motor doing that and its because that hole is open to drain fast while you run it, I Think your mechanic is right, 
That's my story and I am sticking by it


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## ESOX (Nov 20, 2000)

I freaked out one day when I found an ugly puddle of emulsified goo leaking out of that hole on my Merc. Turned out some moron didnt tighten the oil resivour cap all the way. Any water or oil thats under the cowl, will eventually come out down there.


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## davesdecoys (Oct 2, 2004)

Well Steve YPSI, I think that is the best info. I've rec'd! Makes perefectly good sense. I'll try to clean that hole out. Thanks! you da man !!! Daves Decoy Shop


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## steve ypsi (Nov 24, 2002)

Dave, where that hole is there is just about the thickness of a 1/8 inch or less so if you use a drill to open it don't drill far in, I had a heavy stiff wire so I had to open it slightly to get the wire in and the hole go's in a up direction , that area above the the hole hold's about one or 2 cups of water. Jezz i never thought about it that day but I mess with model airplane's and I use Piano wire all the time, its spring steel that can be bent, I looked in the garage and never thought about the piano wire I use in the house, if you know some one into model air planes they always have some extra, comes in .020 to .078, it would have been a lot better because it can be bent also but is very stiff. you only need about 8 inchs, 4 inchs for your hand and 3 or 4 to clean the hole up to that cavity that holds the water


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## davesdecoys (Oct 2, 2004)

Hey Steve, I'm a banjo player so I think my 4th string fits the wire size description your talking about. I'll give that a try & that's an excellent idea by the way. Now will I have to take the lower unit off to access the hole your talking about or can I just use the wire in the little holes where the lower unit connects to run the wire through or maybe even up through the exhaust port at the bottom near the prop? The stuff seems to leak from everywhere! I'm sure this 8hp Johnson has got to look quite a bit different than your Merc but still has the same concepts. Thanks for the great info.. Dave's Decoy Shop-David


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## steve ypsi (Nov 24, 2002)

I am posting 2 photo's of lower unit's the one is a blue 1990 15 HP evinrude with a tooth pick stuck in the hole showing the up angle, I didn't have to clean this one, it was clear, being newer this one wasn't plugged
the second shows a 6 white merc 1961 with two holes, the lower one was the one that was pluged it has a piece of bent wire I put in for the photo to show where the drain hole is , the other has a tooth pick in it. the bottom one was the one I enlarged just a tiny bit so I could get that thicker wire in, it was really plugged tight, took me a hour or so to get the crap out of it from the top(I had the lower end off and I could see it easy to get the stuff in that small depression) so it would drain, I kept pouring water in the depression after running the wire up and cleaning it from the bottom with a stiff wire, and finaly got it to flow out, it was so plugged it looked like part of the casting from the inside. where that wire is the hole just go's in less than a 1/8 of a inch and then it go's almost straight up


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## davesdecoys (Oct 2, 2004)

Hi Steve! Sorry I didn't reply sooner. I just got home from a goose hunting trip. I'm hoping I can get after my motor tomorrow to get those holes cleaned out. Thanks for the photos. That's pretty big of ya to take the time out to do that for a greenhorn boat motor mechanic like myself! I'll let ya know how things turned out when I'm done. Again, thanks for all the help !! Dave's Decoy Shop-David


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