lower unit exhaust build up

[joshrogel]

Hello all,

I have an 1972 85hp Johnson, with ele shift controls.

The problem i am seeing is that exhaust oil goop is building up around the prop. is seems like a great amount. is this normal?

Also, i just pulled my lower unit and every wheres inside is covered is exhaust oil. I have already replaced the triangle thick gasket for the exhaust pipe.

Any thoughts on this?

 

[oldcatamount]

Re: lower unit exhaust build up

Could be a couple of things. One is, the motor is running to cold. Is there a thermostat in it and, if so, is it working? Another issue could be wrong plugs or wrong plug gaps. I would suggest a compression test and then an ignition test. Also, are you using TWC oil mixed at 50:1?

 

[joshrogel]

Re: lower unit exhaust build up

I just ran compression check. all 4 @ 120psi. Just rebuild carb, just installed new champ plugs, just adjusted gap to .012. Motor runs fine, just exhaust oil is building up.
This motor has kind of always done this, just trying to figure out why.
Not sure if there is a thermostat, will need to look into this option.

using twc oil mixed at 50:1.

 

[oldcatamount]

Re: lower unit exhaust build up

Plugs gapped at .012? Is that a typo? Just guesiing here but, I think the plugs should be .030 (or a bit more).

 

[boobie]

Re: lower unit exhaust build up

The mtr should run about 140 * at idle after being warmed up.

 

[steelespike]

Re: lower unit exhaust build up

Are you running in a barrel?it's normal for heavy buildup of waste fuel.Some oil is burned the rest is discharged.Some out the exhaust other through the fuel system.Even motors in normal operation will drip fuel residue out the exhaust on the trailer.
Older outboards just discharge it into the water.Some of the things suggested could also increase discharge.
What is it that you set to .012?

 

[joshrogel]

Re: lower unit exhaust build up

Are you running in a barrel?it's normal for heavy buildup of waste fuel.Some oil is burned the rest is discharged.Some out the exhaust other through the fuel system.Even motors in normal operation will drip fuel residue out the exhaust on the trailer.
Older outboards just discharge it into the water.Some of the things suggested could also increase discharge.
What is it that you set to .012?

Sorry for the confusion.
Plug gap is set to .030
Points gap set to .010 not .012. I must of been thinking of something else.

Running on muffs, i have a trolling plate on and i set it to down position. It just covered in oil residue.
Not to mention that is smokes like a chimney, guess this could be due to the oil I'm using.

 

[oldcatamount]

Re: lower unit exhaust build up

I'm thinking the points should be set at .020. How old are the points?

 

[joshrogel]

Re: lower unit exhaust build up

Manual says that the points should be .010, slightly used set to around .012.

So what I am gathering, is that it is normal to see oil exhaust build up around the lower unit.

 

[F_R]

Re: lower unit exhaust build up

Don't fret about it. You put oil in the gas. Every morsel of that oil goes through the engine to lubricate the moving parts. Some of it then burns and makes smoke. The rest of it goes out the exhaust. That's just the way it is.

BTW, points gap is .010" for new points, .009" for used ones.

 

[joshrogel]

Re: lower unit exhaust build up

Don't fret about it. You put oil in the gas. Every morsel of that oil goes through the engine to lubricate the moving parts. Some of it then burns and makes smoke. The rest of it goes out the exhaust. That's just the way it is.

Sounds good. Thanks for the replies.