Re: Oil / fuel leaking into area behind transom
I always disconnect my fuel line at the engine before I take the boat out of the water or if it is sitting at the dock and not being used. When I first noticed this problem someone suggested that I could run the engine with the fuel line disconnected until the idle begins to stumble. This uses some of the fuel in the bowls and reduces the spillage. Someone else commented that running the engine out of fuel is hazardous to the engine because the fuel/oil mix is the all that lubricates the engine. The point being that if one or more cylinders runs out of the fuel/oil mix while the engine is still running those cylinders may suffer damage. I think this is a very legitament point especially if you concider that it is probably the same cylinder that would run out first every time. It would result in chronic wear to that one cylinder.
It sounds like you are trailering with the fuel line still attached to the motor. If that is the case, when you tilt the motor up, the pressure in the fuel line is probably forcing the fuel past the float needles and you are getting spillage into the splash well. Removing the fuel line from the engine before trailering will probably eliminate most of the spillage.
For myself, I remove the fuel line as soon as I get to the ramp. I will let it run for a few second (maybe 15 seconds) but not long enough to have the idle stumble.
Keeping the detractors in mind, develope a proceedure you are comfortable with.
