Help! Foamy Oil Residue at Exhaust

[tntgrady]

Hello, I am looking for some help on this one. I have a 1999 Mercury 8 horse that I use for trolling the Great Lakes. I noticed after I run the motor I have a large amount of white foamy oil residue coming out of the center of the prop. It actually completly fills the cavity behind the prop. I talked to my dealer and he said it is due to un-burt oil from the exhaust. I am using amsoil snythetic at 80:1. Has anyone heard of this or ran into this problem? I drained the lower gear oil and it looked like brand new no water, however it was a little low.

 

[Scali]

Re: Help! Foamy Oil Residue at Exhaust

means nothing, I see it all the time, like turkey gravey a little { sorry for that comparo } it's spent gas & oil, means nothing but if anything a good sign

 

[timmathis]

Re: Help! Foamy Oil Residue at Exhaust

A little foam is O.K.

 

[Moody Blue]

Re: Help! Foamy Oil Residue at Exhaust

Had similar thing on a 9.9 evinrude that was used 90% of the time trolling. On advice from this forum I adjusted the spark plug gaps 0.010" larger. The motor runs smoother for extended idles and the oily crud is almost non-existant now. The occassional full speed run down the lake helps keep it clean as well.

 

[tntgrady]

Re: Help! Foamy Oil Residue at Exhaust

Thanks for the input. I was told it might help to run regular oil and not the synthetic. The synthetic does not burn up as much in the engine. Anybody know if this is true? I will try opening up the spark plug gap and see what happens.