Merc 20 hp 1979 - black goo from ignition?

[jpw1488]

I have a Mercury 20 hp (Merc 20 1979) that was given to me in okay shape, but needed a lot of work. I have it running pretty well, but there’s a couple issues still. When I got the motor I noticed there was a ton of black sticky gunk in the lower pan which I thought was dried oil or grease. Cleaned it out with degreaser. After running it a little I’m noticing more goo on the ignition wires coming down from flywheel and near power pack. I guess I’m looking at pulling the flywheel now to see what condition the ignition components are in. Could this be the stator melting? I realized that someone had put J8C Champion plugs in the motor instead of the L78V surface gaps. Would that cause significant increase in heat upstream in the ignition? I didn’t run it much before realizing those were incorrect plugs, but who knows how long the previous owner ran them. Also I’m getting a faint slightly metallic clicking/ticking sound under the cowling mostly at WOT. I have a video with sound where you can hear it if I can figure out how to upload it on here. Possibly arcing? Motor runs pretty well otherwise for now...

Any thoughts or suggestions?

 

[tommarvin]

#1 So were is the black stick gunk coming from in the lower pan,clean the motor and look for leaks/goo like your doing..
2.If you think the stator is burning up it probably is,, better pull the flywheel with the correct puller so you dont destroy the flywheel/stator expensive.
3.Always install the Mercury manual, they know more than us.
4. Dont take it personal, you have to something hard to up load picture,its not that easy.
5.You put two stroke oil in the gas?
6.When we got our boat there was a quart to much engine oil is both motors, the point, drain and fill the lower unit with 100% synthetic stock marine gear lube "AKA" Amsoil, install new seals I know they cost a buck each dont cheap out its your boat man. High rpm.
7. hang in there you are working your way through a old motor, and doing a great job.
8, You changed the impeller didnt you?

 

[jpw1488]

Thanks for the reply. I’ve done all the basics on this engine and I’ve restored several old evinrudes prior to tackling this mercury. This one has been challenging in its own way.

Resealed lower unit
New impeller, water pump seals and gaskets
Engine has 130 lbs compression top and bottom
Good spark upper and lower
Carb clean and rebuild kit
new fuel pump
cooling well
new prop
running strong except for the above
50:1 mix

I’m mostly wondering if the J8C plugs being too hot and the wrong style could have caused overheating in stator and if this is worth chasing if it’s running well. I understand the coating on the coils on these motors can melt. Can the coils, once exposed, arc to the block or flywheel? Possible to damage the expensive components of this ignition by running as is?

 

[Chinewalker]

The metallic sound is likely the recoil pawls pinging on the flywheel. Give a gentle, brief tug to the recoil handle while running and see if it gets briefly louder, then goes away.

The plugs likely didn't cause much of an issue. They're short reach (3/8") plugs, so if anything, I'd think they'd run a little cooler.

 

[jpw1488]

Thanks for the info. Makes sense for that to be the recoil pawls. I’ll check it out. I may still pull the flywheel if it’s not too difficult to see what condition the stator/coils are in. Doesn’t look like the coils are all that expensive to replace.