oil coming out of exhaust

magikstik

Cadet
Joined
Jun 1, 2010
Messages
14
What does it mean when you have oil coming from the two exhaust ports in the rear of the motor just below the powerhead? 1989 135 Mariner
 
Last edited:

will941s

Chief Petty Officer
Joined
Oct 1, 2007
Messages
540
Re: oil coming out of exhaust

It means you have it set rich at idle. Those are your idle relief ports, when the motor is in the water at idle there is'nt enough exhaust pressure to force exhaust through the prop, so thats where it comes out at. The oil is just whats left that did'nt burn. You probably foul plugs pretty often, and may have a little rough idle because of all the oil. You could lean the carbs a little bit by rotating the idle screw a hair clockwise, but thats risky as far as knocking them out of whack. Just make sure your running the oil fuel mixture at 50:1 and keep on boating.
 
Top