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Weak spark on 15HP 1993 Evinrude, Still

S

sanssouci

New member
I have a 1993 15 H.P. 2 stroke Evinrude. I run this thing all the time on the dinghy for my sailboat. About 2 (now 6) weeks ago I hit a clump of seaweed and it nearly instantly overheated and I manually shut it down quickly.

Then it would not restart. I noticed I had burnt out the ground wire on the power pack and replaced it. Then the engine worked again but gradually, over a few days, started taking more and more pulls to get started.

Eventually it would not start at all.

I was getting spark on both plugs but it was VERY WEAK. With my DVA meter I read only 2 Volts on either orange wire leaving the power pack and heading to the ignition coil.

I then replaced everything electrical on the motor - I replaced the plugs, the plug wires, the power pack, the ignition coil, and everything under the flywheel. I rewired all the grounds. I even added new wires to ground the grounds together to make sure everything was well grounded. I left the kill switch out of the loop.

I get good voltage now going into the ignition coil and when I pull the plugs out and look at them, I can see spark. It still looks like a weak spark. Either way, when I put the plugs back in and crank the engine I still get nothing. All the electrical is checking out according to the manual I have and testing with a DVA meter and Ohm meter.

I've opened the carb and sprayed starter fluid into it - nothing. I've removed the plugs and spray gas straight in there, closed it back up, and tried and nothing.

I've checked compression on both cylinders and its about 85psi, which is what it has always been.

I've disconnected the kill cord to take it out of the loop.

I'm at a loss. All my mechanic friends are out of options. I'm hoping the internet world may have a suggestion before I turn it into an anchor.

Thanks for any tips!!

Justin
s/v Sans Souci
 
Test for spark using a tool where you can adjust the gap.-----So , does spark jump across a gap of 5/16" on both leads , yes or no ?
 
Ok, I tested it with a gap tester and this thing will jump nearly an inch.

I'm assuming that means I've been chasing my tail rebuilding the electrical circuit.

I'm going to relook other things but - any suggestions?

I've literally sprayed starter fluid thru the carb with nothing and squirted gas in the cylinder, reattached the plug, and got nothing. Compression looks good.
 
Correct , you have now done a proper spark check on this motor.----Sorry , you have been chasing your tail.-----Checked the flywheel key ?
 
I'll check which I have at the moment tomorrow when .back out there. I've switched them around during testing. Yesterday I didn't switch those but did switch the spark plug wires just in case they we're backwards.
 
It's a different sort of spark plug tester. That one just has a light, the other type allows the spark to jump a certain measured distance.
 
racerone said:
Orange / blue stripe wire going to coil for top cylinder ??
Click to expand...


Good news! It turns out I had the orange/blue and orange wires criss-crossed from a prior troubleshooting session. Put these on correctly and that worked out.

So, for the internet, my outboard overheated and burned out some wires.

After replacing lots of obvious burned wires I pulled off the flywheel and the ignition coil was melted. This was no longer manufactured and I ordered a CDI component that was touted to work in lieu of it. I put it all back together and it still didn't work. I then replaced every electrical item on the engine and still no love. Then, thinking that possibly that CDI part was wrong I ordered a used ignition coil off eBay and installed that. After figuring out my criss-crossed wires (as above) everything is now working.

Now I have to go check to see if my sailboat is still floating after not seeing her for 7 weeks!

Thanks,
Justin
 
racerone said:
Orange / blue stripe wire going to coil for top cylinder ??
Click to expand...

Bad news. When I wrote earlier, I started my motor on earmuffs and it ran great. I then loaded it up and took it down to my dinghy and installed it. I ran it in the water and it took about 3 pulls to start (fine) and I did a quick 5 minute test ride at all throttle levels.

Then I parked it and came back three hours later and it wouldn't start. It felt like it kinda wanted to start but wouldn't. I put on the spark gap checker and its still jumping nearly an inch. After trying to start it again 10s of times it eventually kicked on and I throttled up and it ran great all the way out to my sailboat, high idled in neutral while I checked out my big boat, and then full throttle back to the dock. It was running for a full 30 minutes without shutting off.

Then I shut it off and tried to restart it and it took about 5 pulls, felt very sluggish, and restarted. Then would not start again with 10 pulls. Then I packed up as it was dark and frustrating.

Any tips on where to start? I'm thinking blown head gasket or something as the original issue was a severe and quick overheat. Prior to that event this was a solid 2 pull outboard - 1 pull with the choke engaged, release choke, pull and it started like clockwork 2 times a day everyday.

Thanks!!

Justin
 
Good news now. I came home and ordered a carb rebuild kit and a head gasket kit but then went out to the dinghy the next day and the engine started right up. Then started the next two days as well and ran without issue. I believe it may have just needed that fuel run thru after it sat out of the water for a month as I fixed the electrical. All is well now but I will rebuild the carb and maybe change the head gaskets next time I pull the outboard for a regular service.

Thanks for everyones help!

Justin
 
Justin, you should do a compression test and see if there are consequences from that overheating. In my experience, when wires are melted, there can be permanent damage. Maybe you don't have a compression gauge, but it would be a great investment. Often, a motor will recover after an overheat, but in time will continue piston deterioration and eventually fail completely. The impeller should be replaced as we all know that it ran dry and heated up, possibly getting injured.
 
timguy said:
Justin, you should do a compression test and see if there are consequences from that overheating. In my experience, when wires are melted, there can be permanent damage. Maybe you don't have a compression gauge, but it would be a great investment. Often, a motor will recover after an overheat, but in time will continue piston deterioration and eventually fail completely. The impeller should be replaced as we all know that it ran dry and heated up, possibly getting injured.
Click to expand...

I did a compression test and it came back at 80psi and 85psi. Not great but the same readings as when I bought this engine 3 years ago. As I mentioned above it is running great with a great pee stream so I didn't change the impeller during all this. I really dread dropping the lower unit and trying to get it back on with that shifting screw.

That said, today when I was running it the throttle cable sheared in half. This was my fault as I must have put it in the wrong way when I put everything back together again the other day. So, I got to come in the 1/2 mile from my sailboat today with a finger throttle and - thanks to this forum - Marineengine.com gets another $100+ of my money for a new cable. By the time I'm done this will be a new 25 year old outboard.

Justin
 
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