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Discussion Starter · #1 ·
I have an OMC 9.9 HP 2 cycle outboard (about 12 years old, but less than 200 hours I estimate) engine that has been discussed here before as I searched for the reason it would start and idle well, but would not develop much power and full rpm when under load (did seem to rpm up fine in neutral). I had been fighting a fuel problem assumption and did about 10 days ago get it running after a long warm up with slow run of about 20 minutes down the lake. The engine then "caught" and ran fine for a couple of hours. I took it out again a couple days ago with fresh gas with a good shot of Sea Foam, figuring this would be the real fix. The engine has plugs with less than 10 hours on them and a new fuel hose/pump to the tank. The latter hose item was first used on the 10 day ago run.

Well, this time it would not start. It did turn-over a few time on the first or second pull, then nothing. I fished for a while on electric motors and periodically tried to start the engine. It would after left to sit/evaporate/whatever for 15 minutes or so run over one or two cycles then nothing.

Tonight I figured I'd check for spark...this engine is really dead. I use an old "trick" have used in the past to see if there is any spark when I pull the starter rope. It is hard to see the plug area when on the rope side. I took an old spark plug and attached one spark plug lead to it. I tightly wrapped a a piece of bare wire around the threaded area of the test plug and another piece of bare wire about the metal (unpainted) that makes up the "nut" head on one of the installed spark plugs... and used a clip wire to connect the two. This I recall allowed me to see a spark even in daylight when doing the same on small mower engines and the like.

I pulled the starter rope a few times and was unable to see any spark. My assumption is the test plug being in the open air would fire even if the spark was weak.. I saw no spark whatsoever. Is this test method the problem or does it look like I have a dead ignition? I think the ignition is a magneto and it seems to have a coil or similar element - where do I look next for a spark? to verify "no spark" is being delivered? :thanku:
 

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Old Stonebreaker
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From what you've described, I'd say it's time for new coils. Assuming this is a two cyl, I can't see both plug wires going bad at once. If you can get a plug wire out of the coil, you could try a new plug wire before condemning the coils.
HTH,
Mike
 

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Discussion Starter · #3 ·
Yes, a two cylinder. I can test the other plug to see if it too is dead. I think there is a coil laying horizontal across the back side of the engine, above the head/plugs... I'll look at the wires. There isn't a distributor that I can recall seeing, do both plugs fire in parallel - from the same magneto pulse?

I think I should be able to read back through the spark plug wire to the coil and to ground with an ohm meter, and if that is open the coil has to be bad or has a broken ground connection, right? What resistance should I expect to see in the coil, a couple hundred ohms?:thThumbsU

Does it seem possible for a coil failure to behave the way my engine has been misbehaving? That is starts easily and then has trouble developing power, just like fuel/mixture problems. Then after a long running warm up to suddenly clear and let the engine run about normally. That said it is now dead, no more starting.

Speaking of mixture, I did "screw around" with the idle speed carburetor adjustment - is about 1.5 turns from seated about the right place to start with that setting? There I was a little concerned that the screw spring was very compressed when I turned the needle valve in to the seated position, made me concerned I might tighten too much.

The owner manual does not support any work at this level.:lalala:
 

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Old Iron......Forever
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Does it have a stator or points? I had a 60hp Merc that would fire the plugs out of the hole and in the hole nothing. Stator had to be changed.
 

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Discussion Starter · #5 ·
No points, it is a 1997/8 engine, so fairly modern. I'm not sure about a "stator".. are you talking about the ignition pick-up at the flywheel? I'm saying more than I've seen on the subject engine, but I have taken small tractor, lawn mower, etc., engines apart for various repairs. I am familiar with the looks of a vertical (crankshaft) engines with the flywheel on top under a cover.. from the way the rope pull and spark plugs are oriented I'd guess that is the orientation of the OMC engine.

Again, if I can not measure some continuity back through the ignition coil to ground, I'd assume the coil is open.. needs replacing.
 

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Discussion Starter · #6 ·
I found a magneto test procedure on the web that looks good and requires only a few tools, including a volt-ohm-meter, which I have.

The first step is to remove the shroud to uncover the flywheel and expose the magneto. I assume on a OMC Evinrude that means removing the rope starting housing - is that correct? I am just thinking of what the engine looks like, I have not yet gone to the boat to look.

The test procedure tests for magneto open and short (so the ground wire has to be removed to check for a short - thus one has to expose the flywheel) and interesting for voltage output with a simple volt meter. Here one rotates the flywheel by hand and looks for some induced voltage - not the full spark voltage. All this said, makes me wonder about the "coil", I test procedure I read assume the spark plug is driven directly from the magento - a coil suppose an additional voltage step-up I assume.

Still, I assume my spark test has already established there is no spark. I'd not expect to learn more from the above test then the fault is the coil, the magneto or some wire problem - open ground on one side of the magneto perhaps.
 

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I dont believe that Evinrude/Johnson were still "OMC" by then; I know they arent now!;
the last time I had a boat, it had an '82 25HP Johnson; only ever had 1 problem; somehow the carb bowl screws vibrated loose and the bowl dropped about 1/2"; the way the carb sat in there it wasnt able to fall completely "off" and it actually still ran! just leaked fuel like a sieve; I re attached the bowl and got a couple more good years from it before I sold it.
Ive worked on alot of older OMC outboards; (old enough to have points) and on about every single one that ever needed any work at all the coils were all cracked up.
they have 2 sets of points and 2 coils; basically a seperate ignition system for each cylinder; so if one craps out you can still get back to shore; (though under reduced power on account of running on 1/2 an engine)
 

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Discussion Starter · #8 ·
Interesting, the running on one cylinder could be what was going on if it is also possible that the condition can be intermittent... the engine used to correct itself after running for a while. I'd not say it ran rough, just low power, less than half - maybe more like an 1/8th.

No gas leaks.

I'll check the other spark plug too to see if it is also dead.

Again, mine is a small, 2 cylinder 9.9 HP. The manual says OMC - was purchased new in 1998, believe it is a 1997 model.
 

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Old Stonebreaker
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That's what my '54 'Rude did when the coils were going out. Run on one cyl for awhile and then maybe go back to two, then die and wouldn't start for 1/2 hr. Finally just wouldn't start. Changed the coils and points and now it purrs like a kitten on cream!! I just hope the new coils last as long as the originals did.
Mike
 

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Discussion Starter · #10 ·
This is just a follow-up on clearing the problem. The problem was a "dead" Power Pack (the electronics and SCR circuits that drive the two HV coils). I replaced the Power Pack (about $90 delivered) and have had the boat on the water once. Seems to be working well.:thanku:
 

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Discussion Starter · #12 ·
Ha, NJ isn't that far North... lake fishing is comfortable into November... I like a jacket a lot better than sweating in the hot sun with high humidity.

Speaking of winterizing what's the key, make sure all the water is drained out? Not making fun, but admit I've stored an outboard motor outside for about 25 years and the only winterizing I've done is cover it with a tarp (boat cover) and run the gas out - until the engine stops before taking it out of the water.

As for the problem, I've been screwing around with this engine for over a year and always thought it was a fuel problem until it completely died and I could see there was no (or seldom) spark. Even the intermittent spark failure was unexpected. I hope someone following along who has a similar problem will consider that the (almost) always reliable electronic ignition may be the culprit.
 

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My brother in law used to spray a 'fogging' mist into the intake until a running engine stopped. Apparently, it coats the cylinder walls with something to prevent oxidation. He also used to change the lower unit grease. Open the drain plug at the bottom, and then open the one about 6-9" up. The grease would fall out. If it was milky, there was water leaking in that could freeze and crack the gearcase / transmission. To refill, put the grease tube into the open 'bottom' plug hole, and squeeze until it runs out the top, then quickly insert the bottom plug so it doesn't all fall out, followed by the top plug.
That's all I remember. Oh, if you have fuel in a tank that you cannot drain, get some StaBul [brand?] fuel stabilizer so it doesn't turn to gum over the winter.
tom
 

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Discussion Starter · #14 ·
Right on the lower unit grease/oil. I have changed once-in-a-while, not every year. My engine gets light use, but, thanks on the heads-up about looking for water in the oil before freezing weather comes. Come November, I'll drain the lower unit and look for any signs of water.

I bet your BIL is one who manages to get 25 years out of an engine. I am on my second engine in 25 years. The first saw more use, but it also was "feed" 100:1 gas/oil, per the then recommended mix from Johnson (it was a Johnson 9.9) As may have be stated here in this thread, I was told by a dealer mechanic that the engine was worn out when I took it if for a tune-up in 1997. Thus, the Evinrude 9.9 which began its life (new) with me at that time. It has been run on 50:1 and I hope it will not wear out before I do. As noted, I just replaced the ignition Power Pack.:thThumbsU
 
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