Paul Dougherty wrote:

Hi,
I have a 1985 25HP Mariner 2 stroke outboard. After a run to a
fishing spot I stop the motor and after a few minutes there is a
rainbow of a gas/oil slick on the water. After a few minutes is
dissipates. What is causing this? I do not want to be a polluter. I
can not tell where this is coming from. The fuel lines do not have any
leaks.
Does anyone have any ideas?

Paul


Nothing abnormal with your elderly two stroke.

Hi,
I have a 1985 25HP Mariner 2 stroke outboard. After a run to a
fishing spot I stop the motor and after a few minutes there is a
rainbow of a gas/oil slick on the water. After a few minutes is
dissipates. What is causing this? I do not want to be a polluter. I
can not tell where this is coming from. The fuel lines do not have any
leaks.
Does anyone have any ideas?

Paul

If it really bothers you, try floating an oil absorbing "diaper" off the
transom when you stop.

You'll get some of the petro-chemical residue, but not all of it. Still,
capturing some is better than capturing none.

(If the slick was constant, you'd have to check for leaking fuel)

Paul Dougherty wrote:

Hi,
I have a 1985 25HP Mariner 2 stroke outboard. After a run to a
fishing spot I stop the motor and after a few minutes there is a
rainbow of a gas/oil slick on the water. After a few minutes is
dissipates. What is causing this? I do not want to be a polluter. I
can not tell where this is coming from. The fuel lines do not have any
leaks.
Does anyone have any ideas?

That's normal for a 2-stroke, especially an older one. A little unburnt
gas/oil mix always finds it's way from the intake to the exhaust port
since they're both open for a brief moment. In the water, a very small
amount of gas and oil can look like a lot.

If you're really concerned about it (I'm wouldn't be), you can move up
to a 4-stroke outboard.


--
~/Garth - 1966 Glastron V-142 Skiflite: "Blue-Boat"
"There is nothing - absolutely nothing - half so much worth doing
as simply messing about in boats."
-Kenneth Grahame, The Wind in the Willows

It could be normal but if it has increased suddenly it could be a bad fuel
pump. I had an increase of post-shutdown leakage on a 225 Merc. A few
trips later it started running rough. The mechanic found that the fuel pump
had a leak into the crankcase. Fixing it solved both problems and also
improved fuel mileage.


"Paul Dougherty" wrote in message
om...
Hi,
I have a 1985 25HP Mariner 2 stroke outboard. After a run to a
fishing spot I stop the motor and after a few minutes there is a
rainbow of a gas/oil slick on the water. After a few minutes is
dissipates. What is causing this? I do not want to be a polluter. I
can not tell where this is coming from. The fuel lines do not have any
leaks.
Does anyone have any ideas?

Paul

Thanks for all the replies. This seems to be a normal issue. I will
look into the fuel pump though.
Paul

"Bill S" wrote in message . com...
It could be normal but if it has increased suddenly it could be a bad fuel
pump. I had an increase of post-shutdown leakage on a 225 Merc. A few
trips later it started running rough. The mechanic found that the fuel pump
had a leak into the crankcase. Fixing it solved both problems and also
improved fuel mileage.


"Paul Dougherty" wrote in message
om...
Hi,
I have a 1985 25HP Mariner 2 stroke outboard. After a run to a
fishing spot I stop the motor and after a few minutes there is a
rainbow of a gas/oil slick on the water. After a few minutes is
dissipates. What is causing this? I do not want to be a polluter. I
can not tell where this is coming from. The fuel lines do not have any
leaks.
Does anyone have any ideas?

Paul