Re: Merc 502 spitting oil
 

Is it dripping from behind the harmonic balancer or is the oil dripping from inside of the front pulley??????
My factory sealed 525sc dripped out the center of the pulley. It barely dripped, but when it was running, it would spray little drops all over.
If its just dripping and not getting flung around, then it probably the oil pan seal.

Re: Merc 502 spitting oil
 

Good point. If the damper has ever been removed (or sometimes if it hasn't), there can be oil creeping thru the bore of the damper and coming out behind the flange washer.

Re: Merc 502 spitting oil
 

Its common practice (or should be) to use some Ultraseal behind washer and bolt for the harmonic balancer. The oil can leak through the keyway slot in the balancer. Easy fix if that is where its coming from.

Re: Merc 502 spitting oil
 

Thats not unusual for these motors. If nothing else was touched before this is most likely where its coming from. I have replaced a couple of vibration dampers with fluidamprs and noticed oil seeping from around the bore on more than one motor.

Re: Merc 502 spitting oil
 

I'm not sure what the "harmonic balancer" is. The lower center pulley has a disk behind it that has the timing marks on it (Is that the Harmonic balancer?) Anyway if I reach behind that disk to it's center, I get oil on my finger tips. Look at the center of my 2nd pic. Oil dripped out and did not get slung anywhere else in the bilge. Each engine lost approx a tablespoon over 2 hr run at RPM's from 3500 to 4000 with a few minutes of 5,000 RPM's.

Re: Merc 502 spitting oil
 

That disk with the timing marks is the balancer. It sounds like the oil is seeping through just enough to be an annoyance. I would monitor it if you are still running the boat and if you are not using it, take the lower pulley and damper off. You will gain access to the front seal and you will have a much clearer view of the timing chain cover and any other possible areas for the oil to leak out. That isn't a bad project to do. You will need a damper puller, a torque wrench, and definitely some Ultraseal like Formula31 mentioned.

Re: Merc 502 spitting oil
 

If its not getting slung around and its behind the the harmonic balancer(yes, thats the disc with the timing marks :D ), then the timing cover gasket is probably leaking in the corners or where it meets the oil pan. It's a pain in the a$$ to get them resealed completely once they are removed.

Re: Merc 502 spitting oil
 

If you pull the balancer check the snout for a groove cut into it from the front seal. It always amazes me that a rubber seal can groove a steel part. Anyway it to is an easy fix. They make a sleeve that goes over the balancer snout and then replace the seal in the timing chain cover. Good luck.

Re: Merc 502 spitting oil
 

Thanks for the feedback.....
My mechanic says the material cost in a non-issue, but the job should take aprox 2 hours per motor....On the plus side, he is only charging me $50.00 per hour. Should I just do it, or wait and see how bad the leak gets in the spring?

Re: Merc 502 spitting oil
 

Do it Now! While the boat's "down". That's what winter's for. (Only thing I can figure) It won't fix itself and it could make a big mess of your boat, ruin a day or weekend, and still have to be fixed.