1970 Johnson 20HP leaking grease in water?

[kawaboy-zx11]

Hi, my 1970 johnson 20hp has been leaving a film on the water, thought it might be gas but i took the hood off and didnt see any gas leaks from the carb or fuel line....pretty dry under the hood. so then i started thinking my lower unit must not be sealed good so i drained it out and there is no water in the lube. the film shows up on the water when i stop to fish, and it keeps showing up for a few minutes then it goes away after i have sat without it running for a while. any ideas what this petroleum film on the water could be from? i was planning on resealing the lower unit but the grease had no water in it. Thanks, Dennis

 

[SparkieBoat]

could be oil residue that comes out of your exhaust. but you could drain and replace your gearcase oil and make sure you are not getting water into it.

 

[kawaboy-zx11]

yes, i did drain the gear case oil, haven't replaced it yet because i still am not sure if i need to reseal the gear case, would you say that since there was no water in the oil that its ok to put back together? also the gasket under my shift shaft cover plate now has a little piece missing, is that a gasket needed (for a water tight seal) to keep water out of the leg? its omc/johnson part # 0304023. Thanks

 

[SparkieBoat]

if you have a damaged gasket, you should replace it. no water in the gearcase is a good sign for sure. you could pressure test it, but if you do not have a way to do that I think that you are ok. the fuel/oil residue that comes out of your exhaust would explain the oily film especially if you are idling a little rich.

 

[kawaboy-zx11]

ok thanks, i have been mixing my gas and oil a bit rich, i have been using 4 oz of oil for 1 gallon of gas, i really should be using 3 oz oil. i went ahead and put it all back together and luckily my local marina had the shifter cover gasket for $1.60 out the door. so since there was no water in my crankcase i should be good to go, i just wanted to do a precautionary check on here because the LAST thing i want to do is buy a new lower unit for this old motor. Thanks again for the help!

 

[SparkieBoat]

change that oil every year.