1963 evinrude 18hp leaking oil?

[ngriser]

I have an oil leak in the lower unit somewhere. It only seems to leak when the motor is running. Since the leak is under the water how can I figure out where it is leaking from? What are some of the more common causes and locations of oil leaks that I can look for?

 

[SeaKaye12]

Your motor has a two-piece lower unit. It can leak oil from these places:

(1) Prop shaft seal behind propeller
(2) Drive Shaft Seal undeer the impeller
(3) Shift Shaft Seal
(4) The phillips head screw in the skeg
(5) The joint of the skeg and the gear housing with the 6 screws
(6) The oil fill screw and the vent screw gaskets

The method typically used to determine which areas are leaking is to pressure/vacuum test the lower unit. You can have this done at a shop or you can make up your own "tester" using a bicycle pump. There are threads and videos that show various cobbled up versions.

In pressure testing...you would first drain the oil .....apply pressure while the unit is submersed and watch to see air bubbles. It's best to drop the lower unit first so you can better observe the seals by the water pump (DS seal and shift shaft seal).

 

[ngriser]

Do you mean take the lower unit off the motor and drop just the lower unit into the water?

 

[ngriser]

I have not been able to find a good video that shows how to do this anybody have a good one they could share

 

[ngriser]

So I drained the oil and it came out nice and clean no signs of water in it. I made a tester with my bike pump and sprayed soapy water on the prop shaft seal behind the propeller, the shift rod seal, the Phillips head screw on the skeg, the joint of the skeg and the gear housing with the six screws, and the oil fill and vent screws. No sings of leakage anywhere. The only place I have not checked is the drive shaft seal under the impeller. But since there is no water in the oil wouldn't this rule out the possibility of that seal leaking anyways. I just replace the impeller and don't want to take off the housing because I would have to clean the rtv off and apply a new seal of rtv. I don't have any more rtv right now so im trying to avoid taking the impeller housing off.

 

[ngriser]

when I run the motor in a trash can I notice oil staring to foam in the water. It doesn't appear that it is leaking from the top part of the motor. But I have check just about everything on the lower unit for leaks?

 

[ngriser]

ok so I just submerged the entire lower unit in water and hooked up the bike pump no bubbles from anywhere? Im going to refill it with oil and fire it up see if im am still getting oil in the water barrel

 

[imported_bowfisher]

What color was the oil?

 

[ngriser]

green looks just like the new stuff I just put it in

 

[silver_bay]

when I run the motor in a trash can I notice oil staring to foam in the water. It doesn't appear that it is leaking from the top part of the motor. But I have check just about everything on the lower unit for leaks?

I suspect you're seeing unburnt oil mixing with water.... It forms a blueish or greyish sludge. I think of it as "snot"

You may also see it drip from the engine after running it... there are some drain holes in the lower unit...

 

[ngriser]

No the oil i see is in the water barrel and is milky brown. i dont see any dripping from the engine. yes there are drain holes in the lower unit what about them?

 

[masterbt]

you are using premix fuel and oil in a barrel not in a lake unburnt oil will build up in drum. what fuel to oil mixture are you using

 

[AlTn]

your description is classic unburned fuel mix typical for running in a barrel...