Is this oil? and where is it coming from?

[frogseatflies]

Hi boaters,

I took my 2005 4-stroke 8hp Mercury out of storage where it's been sitting for 15 months.

To test it and get her tuned up, I put it on a stand with the lower unit submerged in water as usual. As you can see, it's leaked or has been leaking oil etc. It didn't look like this the first few days; it has gradually, over time, built up to this much oil leakage. I know there's a little bit of gas in there because I had spilled just a little in there.

I'm assuming some of you have seen this before.

Do you know where this oil is coming from? Lower unit? etc. And what are your suggestions for fixing. (And any ideas on how to remove the gas/oil from the water in an environmentally-friendly way so that I can dispose of it properly.)

Thanks in advance. See the large photos below.

 

[mr 88]

Re: Is this oil? and where is it coming from?

Probably the residue from your exhaust that comes out the prop.When there cold and you run it with the choke you get unburnt fuel coming out the exhaust.If your concerned that the lower unit may be leaking then you will have to pressure test it or if you run it and its leaking, generally water will get sucked into the drive and when you crack the drain screw you will see tainted oil... Probably the only way to properly dispose it would be to buy those oil soakers they use at service garages and drain the bucket through that as it will shed the water and absorb the oil.

 

[frogseatflies]

Re: Is this oil? and where is it coming from?

That's some good advice. I didn't see any leaking from the lower unit when it was sitting in storage or when I had moved it around, so it does make some sense that it'd be unburnt fuel. And it honestly does smell like gas when I get around the engine and the water bucket.

 

[Chris1956]

Re: Is this oil? and where is it coming from?

Did you lay her up using fogging oil? If so, it could be that as well.

 

[racerone]

Re: Is this oil? and where is it coming from?

Mr 88 the poster mentioned that this is a 4 stroke motor.----------What happens with 4 strokes is that the motor is not always adjusted to be horizontal on the boat or storage stand.--Oil runs into the bottom cylinder.-----Over a long time oil leaks past the piston rings and into the exhaust.---Then on startup it ends up in the water.-----Add some detergent to break up this oil !!

 

[frogseatflies]

Re: Is this oil? and where is it coming from?

I didn't lay her up with fogging oil.

Thanks racerone for your comments as well.