Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

[capnstabbin]

Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

I just started to see this happening and not sure if the leak is something major or not...

The pictures show what I am talking about, I wish I had more info or part names to help this thread get searched, so if makes sence to add in this post please let me know.

 

[Daviet]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

Is it raw gas/oil mixture or does it look like it's burnt oil mixture?

 

[capnstabbin]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

Its definitely a burnt mixture, thats a perfect way of explaining it.

 

[Daviet]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

Most likely and exhaust cover or powerhead gasket is leaking.

 

[capnstabbin]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

Would that be as easy as taking all these bolts out and replacing gaskets..... or is this a major problem?

 

[Daviet]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

First you need to determine if it is an exhaust cover or powerhead gasket that is leaking.
Remove the exhaust housing cover on the rear of the engine so that you can get a good look at it.
If it is just the cover it is not to bad as long as all the bolts come out easily, if it is the power head gasket then the whole power head will have to come off.

 

[capnstabbin]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

So it would have nothing to with the side with a ll the bolts circled above?

 

[Daviet]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

All those bolts hold on the exhaust manifold cover, might be your problem.
Take a look at the parts breakdown and you will see what I am talking about.

 

[capnstabbin]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

Is this some thing that is critical to fix immediately?

IS this a big problem, I mean I have no problem taking the powerhead off (I've never done it but, the engines 35 years old, what do I have to lose?)

Can I wait till the end of the season....?

 

[capnstabbin]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

I wanted to do the piston rings anyway at the end of the season... I mean if I am keeping this engine... and dont plan on buying something else... is it worth doing all this work? is the engine worth it... I was thinking of getting something that didnt dump so much gas and oil into the bay.....going green I guess.

 

[Daviet]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

How long has it been leaking, if you have put up with it for awhile, you can probably wait.
Is it worth the work, only you can ansewer that question. Would I do it if it were mine, yes I would, but I really like those 3 cylinder engines.

 

[capnstabbin]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

Me to... it works well... really well.

 

[Jet Wrench]

I've got the same engine...

I've got the same engine...

Had to replace the power head. It is very easy to remove. You should have an engine lift available to do the work. The power head weighs about 50 Lbs. It will make it easier if you drop the lower unit before taking the head off. More than likely, the gasket between the power head and the exhaust manifold is leaking. Make sure the casting on the power head where it meets the exhaust manifold has not corroded away. You can use some JB Weld to build up those areas and then file smooth so the gasket will mate well. Do yourself a favor and purchase a maintenance manual for the engine. I like these engines as well, bullet proof for sure.

Jet Wrench

 

[capnstabbin]

Re: I've got the same engine...

Re: I've got the same engine...

Hey Jet Wrench thanks for the photos..... I am gonna def. try replace these gaskets and psiton rings while its apart.. gonna wait till this winter... just tooka ride last night for some cocktails.

Other than this slight oil/gas leak out of the exhaust, my other problem(which I will start a new thread for) is that when I take it out of gear after accelerating the timer base sticks a little and it idles high... I have to take the cover after taking it out of gear and push it back like a 1/4 inch.

 

[capnstabbin]

Re: I've got the same engine...

Re: I've got the same engine...

Hey JEt......
Do you have a photo of the bottom of the power head?

 

[capnstabbin]

Re: Oil or Gas/Oil Mix leak in 1976 70 hp Johnson 70EL76

Does anyone have anymore info on this project of removing the power head?