black oily substance from gear case

I have a 1960 Evinrude Sportwin 10hp that runs great at first and then seems to start to load up and run poorly. When we haul out there is a black oily substance coming from a "weep hole" in the gear case, above the prop. It's pretty nasty black stuff, not gear oil. Any suggestions would be greatly appreciated! I should add that I checked the plugs (which were new) and the top cylinder plug is now B-L-A-C-K! The lower plug looked fine. I mixed the fuel at approx. 24:1. Guy I bought it from said the coils and impeller are about 5 years old. This motor is new to me as of this summer. I'm fairly handy with your average Chevy 350, but don't know jack about outboards.
Thanks in advance for any help you can offer.

Re: black oily substance from gear case

It sounds to me that you may be losing your top cylinder. To verify, you could simply let her run and when she starts to load up as you say, remove the spark plug boot from that cylinder and if nothing changes most likely it was not firing at the time. I would then replace that boot and then pull the plug boot from the bottom cylinder. If I am right she will stall.

When pulling boots off of operating motors be sure to use well insulated pliers since it is very high voltage and it can give you a bit of a shock if you are not careful.

The black plug is most likely the oiled gas that went into that cylinder but was not burned. It is now running down your exhaust and dripping out of your drain hole.

Why you are losing a cylinder is work for the more knowledgable people of this forum. Could be a bad coil or perhaps a fouled spark plug.

Re: black oily substance from gear case

agreed

Re: black oily substance from gear case

Thanks for the idea(s), I'll give the cylinder test a shot tonight. I picked up a spark tester last night but never got a chance to try it (wife and kids demanding attention - go figure). Do you know if the coils are interchangeable? I thought I might swap the coils to see if the problem moves to the bottom cylinder. Thanks again for your input, any/all suggestions are welcomed as I'm really moving into uncharted territory here as far as I'm concerned. I'll post my findings as I go. Thanks OptsyEagle and freddyray21.

Re: black oily substance from gear case

also check compression on both cylinders, before spending any money. well the coils are under the flywheel, if no spark on top cylinder, 99% coil. if it were me, i would change everything under the flywheel, coils, points, condensers, and possibly plug wires, then you now it is good, with a carb kit, and new impeller, it should go for another 50 years.

Re: black oily substance from gear case

Thanks Tashasdaddy - I picked a bad time to start this thread - we're hosting a wedding reception at our place this weekend and the wife's not too happy about me sneaking out to work on the outboard while she's workin' on the house - having said that I won't have a chance to revisit the motor until this Sunday at best. Between now and then I'll pick up a compression tester and check the cylinders (I've got a 40 year old one from my dad - but I don't trust it - cracked hose - an inaccurate reading is no better than no reading). Can you recommend a source for the coils/points/etc. Are those parts something I can purchase here?

Thanks again for all the interest in my issue - I'll post the progress on Monday the 29th.

Re: black oily substance from gear case

points condensers http://www.iboats.com/mall/partfinder/?gd_grid_id=601&gd_partfinder=1&gd_poid=111576&gd_row=12

coil http://www.iboats.com/mall/partfinder/?gd_grid_id=1279&gd_partfinder=1&gd_poid=109172&gd_row=53

don't forget the water pump. http://www.iboats.com/mall/partfind...&gd_poid=110980&gd_row=2&**********=549939525

Re: black oily substance from gear case

It sounds to me like you may just have a fouled plug. I would replace the spark plugs. I believe they are Champian J6J. I'm not 100% sure on that because I don't have my parts manuel with me right now. Also, make sure spark plugs are gaped correctly at .030 inch. Anyway, I would change the plugs and check the oil/gas mixture. I believe I was having the same problem because I was mixing 16 to 1 so I changed to 24 to 1 and that seemed to solve the problem. You may also consider putting a can of SEAFOAM in with the fuel in order to clean out your motor. You can buy that at Walmart or any automotive store.

I agree that you should check the compression.

If doing this doesn't fix your problem, then I would replace the coils, points, and condensors. That's always a good idea anyway, because then you know that they're new. points should be gaped at .020 inch.

And of course you need to replace the water pump. I've heard that they should be replaced about every 3 years or so.

Re: black oily substance from gear case

BSDenning- thanks for the specs and info - I'll give that stuff a shot tonight. Here's what transpired over the weekend: Threw the spark tester on and got a nice strong blue spark on both cylinder. Did a compression test and and both cylinders read 75lbs. compression. I'm not sure what they should be but 75 didn't seem too bad. I thought I would mix up some new gas (at 24:1) and try that, along with a couple of new plugs. As you can tell I'm trying every thing I can before having to start taking parts off (which is probably the next step). Not to get off the subject but I managed to twist off one of the clamps that hold the motor to the transom while trying to get it off the boat. I tried to use an ez-out to pull the remainder of the stud out but it wouldn/t budge. I ended up cutting it off with a reciprocating saw between the transom and motor mount. Any suggestions on replacing the mounting screw? is a helicoil and bolt my only option? - I don't want to go too far down this path as I really want to sort out my fouled cylinder, but thought I would ask. Thanks again to all for your input - I really appreciate it.

Re: black oily substance from gear case

That compression reading doesn't sound too bad to me. My 10 hp has a reading of about 89psi in each cylinder, but I would say that I have an exceptionally strong running motor for its age. I think the main thing is that both cylinders need to have pretty close to the same pressure. I've heard that as long as they are within 10% of each other, you are good. I've also heard people say that their motors still run good all the way down to 65 or 70 psi as long as it is the same in both cylinders. You also have the issue of different compression testers giving a little different readings.

If you replace the spark plugs, make sure they're gapped correctly, and run good properly mixed fuel and you still have the same problem with the top cylinder, I would try what you said about switching the coils. If that reverses your problem to the bottom cylinder then you know for a fact that the problem is the coil. Good Luck!

Re: black oily substance from gear case

If the fuel pump diaphram has a hole it can cause the upper cylinder to foul.

Re: black oily substance from gear case

steelespike said:

If the fuel pump diaphram has a hole it can cause the upper cylinder to foul.

Click to expand...

I'm not sure if that model has a fuel pump or not. He could be running on a pressurized tank. 1960 is around the time they switched from pressureized to fuel pumps. Which do you have 1960rudetwin?

Re: black oily substance from gear case

I have a "non" pressurized tank. Sorry for the delayed response. Hope to make further headway tonight with the new plugs and precise fuel mixture. I'll post my findings.

Re: black oily substance from gear case

I pulled the fuel pump diaphram and it seemed "brittle". I did convince myself that I saw a hole/tear right next to the "button" in the middle of the diaphram. The two rubber pieces peeled apart quite easily and there was fuel residue in between the two (not sure if that's relevant or not). I thought I would replace the diaphram, install my new plugs and give it a shot. I'll post an update after I get the part.

Re: black oily substance from gear case

Well, I'm certainly naieve. Thinking I could find a fuel pump diaphragm for $20 almost anywhere. Turns out all I can find is the entire pump for $85! Anyone know where I can buy just the diaphragm for 1960 Sportwin 10hp?