Re: 15 HP Evinrude 1986 white oil in
My guess is that You may not be running the motor fast enough at times, especially when returning to the ramp to warm the motor up if you had been using it mainly for trolling previously. With the oily plugs, & light colored oil coming from the relief hole in the upper rear exhaust housing, it is a indication that the inside of the exhaust housing has a quantity of unburned oil that has mixed with the warm exhaust water.
This being the case, when you pull it out of the water & let the motor set for a while, you will also have a quantity of oil drip out of the prop. This oil will usually be black because it has picked up a lot of carbon inside the exhaust housing. This is normal.
However if you change your oil to a semi-snythetic, this will help some. Also run the motor hard getting back to the launch helps.
As Tash- indicates it is water in the exhaust chamber, but the way this motor is made that is normal.
Look at my
http://www.sschapterpsa.com/ramblings/Johnson 9.9_15.htm article under "Water Passage Thru the Motor"