Oil leaking from motor

[danbouck]

I've got a 1981 Johnson 9.9. I just noticed that there is a little oil leaking out by the prop. Is this Normal? Also last time I had it out it would slip out of gear and rev really high without the prop spinning. Are these related? What is causing this. Any help would be appreciated, thanks

[brifishrgy]

It sounds like your prop needs to be rehubbed ... as for the oil leak grab yourself a gearcase seal kit and replace the seals for the bottom end and all should be good ... if the oil is getting out the water is getting in

Edited May 27, 2007 by brifishrgy

[boatman]

What does the oil look like? Is it black and thin or is it gear oil from your lower unit? You have thru-hub exhaust so if its black and thin its probably unspent fuel and carbon if its gear oil (not as likely) you have a worn out prop seal.

 

Popping out of gear when you're running is probably a worn clutch dog in the lower unit. Just like in a car, when the clutch wears out you start poping out of gear. They are not normally related problems. However, it could be a spun prop, but they normally begin to fail under high torque (trying to plane) not at cruising speed.

[danbouck]

The oil is black and thin. How can I inspect this? I am mechanically inclined and $600 was just put into this motor so I would like to do it myself.

[Bernie]

Its probably oil residue from the exhaust. Could be the type of oil you are using. Some 2 stroke oils leave a residue because they dont burn off easily during combustion. As far as the jumping out of gear does it do it at lower speeds? As boatman has said it may be a worn clutch dog. Put the engine in neutral and spin the prop with your hand. Does it feel fluid or does it spin freely? If it doesnt feel like there is oil in it get it checked out. A pressure test of the lower unit only takes a few minutes at a shop.

[boatman]

The oil is most likely unspent fuel and carbon (99% sure of this). It is very normal. Check your lower unit oil. If there is water in there then you have a problem. If you have a leaky seal water WILL be in the lower unit.

 

As for popping out of gear, take off the prop and inspect for any obvious signs of damage. Test with another known good prop if you can. However, I'm not optimistic enough to believe that is your problem. Explain what you are doing and how you are running when if fails. This would be helpful in troubleshooting the problem.

 

Here is a diagram of your lower unit gears. The clutch dog has two small protrusions on either side that contact the forward and reverse gears. In time the sharp edges round off and starts popping out of gear.

 

http://www.myfishingpictures.com/showphoto...0&password=

[danbouck]

Thanks everyone, Boatman, when it pops out of gear it is when I am going wide open with 3 people in the boat (14 footer). It has never done it with less than 3 people in the boat. Now here is a noobie question, How do I check my lower unit oil? Do I just drain a little and have a look at it?

[boatman]

That is exactly how to check the oil. Make sure you top it back up afterwards. If your seals are so bad that they leak even when the motor is out of the water then you will have free water (not emulsified) in the gearcase. If there is any water in the gearcase it will come out as soon as you open the drain. The oil will be floating on top of it. I sincerely doubt the oil you are seeing is gear oil, but it can't hurt to check anyway. As well, if the lower unit leaks that bad you or your service tech should have noticed the problem before now.

 

As for the popping...does it actually come out of gear? If it does, then I'd say its the clutch dog. Sounds like it is just starting to wear out. A slipping prop might cause the motor to rev high and look like the prop is not spinning, but it will still be in gear. If its your clutch dog it can be very expensive. Usually the most affordable option is to swap out the old lower unit for a used one (about $300). A new clutch dog is about $100, but is usually replaced as a set with both forward and reverse gears (approx $500). If you can do the work yourself (and you're lucky) then you might be able to repair it for around $150 for a clutch dog, new lower unit seals and lube. Or find a used lower unit for $0-400. I know that's not what you want to hear after spending $600 on it.

 

That motor commonly sells for $500-700 in good condition. Less if its not pretty. I'd suggest finding a good parts motor. You can usually buy a non-working outboard cheaper than the sum of the individual parts. For instance, I just bought a 1981 15hp for a friend for $150 that only needed some minor work. If you look around you should be able to find something similar.