1984 Evinrude 9.9 Dripping Oil

[JimS123]

I have old 1950's motors that run at 16:1 or 24:1 and they always have an oil drip from the lower unit's water weep holes. After a few weeks of non use the oil drip usually stops. My issue here is with a "newer" motor that has never dripped before.

The motor has been a kicker for all of its life. Currently has about 350 hours. I do run a low pitch prop to keep the rpms up.

Late August we trolled for about 6 hours straight without stopping. At the end I ran her up to wot to "blow out the stink", as I have always done in the past. No particular issues noted. For the past 6 weeks she has been dripping constantly.

The plugs are clean, with no oil buildup. Looking at them you wouldn't think the motor had idled for 6 hours. The gearcase is full with no water intrusion. The "leak" is certainly unburnt oil from the fuel.

My question is what to do to clean it out to stop the mess. Right now I have a bag over the lower unit. Winterizing has already been done.

As i said, this motor has never done this before.

 

[racerone]

Check the thermostat as a start.

 

[kbait]

Decarb with seafoam. You can add to fuel tank, or shoot into carb. Search 'decarb evinrude' and you'll find lots of procedures.. That'll likely help with the dripping, but as your gearcase is obviously sealed, it's really nothing to stress over. Also, if your low speed mixture needle is set a bit rich, you'll get more gunk..especially after extended trolling.

Good luck!

 

[JimS123]

The plugs are perfectly clean and dry, plus an inspection of the pistons thru the plug holes would indicate no excessive carbon buildup. If the thermostat was an issue and it was running cold, wouldn't oily plugs and carbon buildup show up?