1980 Merc 140 3.0L Problems

[GatorBait]

My engine has been running fine all year so far. The last time we went everything was fine untill we started to come back in to the dock. It started to idle rough and blow black smoke out the back. Can someone help me out with this please?

 

[JustJason]

Re: 1980 Merc 140 3.0L Problems

black smoke is fuel. When was the last time the boat had a full tune up?

 

[GatorBait]

Re: 1980 Merc 140 3.0L Problems

Not since I have owned it in Jan.

Thought I was supposed to commit to timing and not fuel first

Thank you will do the full tune up.

 

[JustJason]

Re: 1980 Merc 140 3.0L Problems

Thought I was supposed to commit to timing and not fuel first

I don't know what you mean by that, but a tune up is a once a season thing.