lower unit oil leak

niteblaster

Cadet
Joined
Jun 9, 2010
Messages
14
I just started my motor today for the first time since I changed the lower unit gear oil and after about 20 seconds of run time its leaking oil. Does anyone know what this hole is called it shows it in my manual but does not mention it at all. I called a repair shop and their diagram does not show it. I have heard it could be un burned 2 stroke oil but would it be coming from here? I did put oil in the spark plug holes for winterization and the plugs fouled and stalled after 20 seconds. Earlier last month while inspecting this hole it appeared to have a small pebble blocking part of it and I tried to remove it but it moved inside. There was never a screw or plug here before and does not show one in the manual.
DSCI1437.jpg

DSCI1438.jpg

I believe it is a 1981-82
 

Gary H NC

Fleet Admiral
Joined
Dec 1, 2005
Messages
8,972
Re: lower unit oil leak

Does it smell like gear oil or more of a fuel-oil smell?

Those holes are just water drains.

Also check the exhaust above the prop and see if the same type oil is coming from there.
It looks really dark to be gear oil if it was just changed.
 

niteblaster

Cadet
Joined
Jun 9, 2010
Messages
14
Re: lower unit oil leak

Thank you for the super quick response. Yes it does have a slight gas smell to it. I don't see any from the exhaust but a small amount also on the other side of the motor. Do you think it is just un burnt oil from the motor?
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: lower unit oil leak

Looks like motor oil to me. Don't know how gear oil would ever reach that hole.

What color gear oil did you put in it? The oil I use is amber colored; after a year it's still not that dark.

For a definitive answer, drain some of your gear oil -- if oil is getting out, water must be getting in.

I don't know that model, but most rudes have a hose running from the bottom of the air silencer to the manifold, to scavenge the oil that collects in the airbox. On my motor that hose comes loose pretty easily and lets oil drain into the water. Not that much oil, though.

Check out the "Decarb" thread in the Engine FAQ section of iboats, looks like maybe your motor could use it.

Are you running that motor in a tub?

If you have a hose attachment that works with that style of water pickup, I'd love to see a pic of it, whenever you get a chance -- I remember seeing one in a store about 25 years ago, but can't recall exactly how it worked. Haven't seen one since. Thanks.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: lower unit oil leak

That is a drain hole, and what you are seeing is oil coming out with the exhaust. You said yourself that you put oil in it for winterization---so much that it fouled the plugs. Well, guess what, you are looking at it.

Get that motor on a boat, and run the heck out of it to burn that crud out of the exhaust and it should be fine. BUT--it still is a 2 stroke, and it still will have a bit of oil going out the exhaust, and you may see some of it. That's life.
 

niteblaster

Cadet
Joined
Jun 9, 2010
Messages
14
Re: lower unit oil leak

Thanks for the help guys. I had it in my pond when I started it and the water pump was flowing nice but it was smoking good and stalled. I pulled it out of the water and noticed the oil coming out pretty good. I pulled both spark plugs and they were wet and had some oil on them. I will try and get a pic of the motor posted tomorrow afternoon with the cowl off. I'm not sure if it has a hose like you mention so hopefully you will be able to tell from the pics tomorrow. I was wondering if it could have been gear lube or not since I didn't shift it while it was running.
 

jasper60103

Commander
Joined
Sep 18, 2008
Messages
2,055
Re: lower unit oil leak

yep, I have the same motor and the same stain, but you have a nicer skeg than me.

hole.jpg
 

niteblaster

Cadet
Joined
Jun 9, 2010
Messages
14
Re: lower unit oil leak

Here are the pics without the cowl. I don't know if it has the hose you mentioned?
DSCI1440-1.jpg


DSCI1439.jpg


I checked the color of the gear lube and this is defanately not gear oil so thanks everyone.
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: lower unit oil leak

" I don't know if it has the hose you mentioned? " it's not visible here, but your engine compartment doesn't look oily.

It's not a "mission critical" part anyway, doesn't affect the running.

If there, it'll be at the bottom of the air silencer whenever you get around to your first carb rebuild. You can look it up on the electronic parts catalogues on shop.evinrude.com if you get curious. Meanwhile, I recommend a couple days of fishing, just to make sure everything's all right.
 
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