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59 Evinrude spark dilema

O

ORDon

New member
I have a 59 Evinrude 18 HP. Here is my problem. When I connect the spark plug tester to a SP wire and the other end to anywhere on the engine I get a really good spark. However when I connect the tester directly to a spark plug - no spark. This happens with the old plugs as well as brand new plugs. Same results on both top and bottom wires. What am I missing?
 
The spark tester has a certain gap that the spark must jump. Likewise, the spark plug has a certain gap that the gap must jump. When you connect them in series, the two gaps become the sum of the two---that is wider----and more difficult for the spark to jump across. Keep in mind that the spark jumps both gaps at the same time--not one then the other.
 
The spark tester I have does not have a gap. It has a small light bulb, probably similar to a timing light. When I said strong spark, it lit up the light bulb quite bright.
However, when I check for a spark across the plug, grounded to the motor so I could see it. No spark.
With the ohm meter set at 40k, I get 7.07k and 7.78k on the coils.
 
Right....I can get 3/8" crackle on my old clunkers. I really think it's critical to get coils set perfectly and points as well. Minimum stator plate play is essential. Always check stator plate body to ground in all throttle positions. NO TOLERANCE for resistance there....it will weaken the effect of the entire system. Many mechanics never even check this. A decent multimeter costs 20 bucks......and you can earn a good living knowing how to use it.
 
When you say stator plate are you referring to the magneto plate the coils, points etc attach to. I will check the ground as you suggest tbough. This thing has been apart so many times this last week, who knows.
 
I have a 65 evinrude trying to diagnose spark. I got a small shock with the old plugs today, going tomorrow to pick up new plugs!
 
I have done everything I can think of. check the coils, good continuity, within spec resistance. Ohm test on condensers, passed according to the article I'm referencing. Cleaned points, 0 continuity, they are making full contact. New plug wires. Good ground between magneto plate and motor. Cleaned all wire connections. Did the hacksaw blade test on the flywheel magnet. It stuck. Bought a adjustable spark guage. No spark at even 1/8". Today I called a local boat shop checking on parts availability. This guy I talked to said he has worked on older Evinrudes for years. The first thing he does when one comes into the shop is strip the magneto and install all new parts. One other thing he said to check for is a leaky seal that can put a film on the points. Guess that's next.
 
If you have no resistance on closed points, they are good. However, you have to measure when they are dry. If there is an oil film on them from a bad crankshaft seal, they will not give you 100 percent continuity, (zero resistance). If the points are clean you will have a running motor if even the seal is leaking......it would take quite some time to build an oil film enough to remove the ability of the breakers points to do their job. Are the plug wires copper core? There has to be zero resistance there too. I have seen where some fools have used carbon core resistance wire on outboards with magneto ignition....this also doesn't work. Are the coils cracked on the underside and arcing to the stator plate......or are the plug wires arcing to the stator plate? Perhaps the plug wires are not fully worked into the depths of the coil outputs. Are the other wires that go to the kill button grounded, or the switch bad? Are the coils set the proper clearance from flywheel magnets? Condensers rarely fail. You can test them by charging them on your lawn mower or something similar. How? Can explain next time if you don't find the problem with the aforementioned information.
 
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I don't think I have an oil issue. I mentioned it only because it is something to check for as well. Plug wires are copper core and new. The coils have no damage that I can see. They are probably 5 years old, replaced before I got the motor. The coil pins have the little ridges and I recently trimmed and reseated the wires. I'll double check the ground on the kill switch wires or in this case the ignition switch. I was getting the inline spark tester light bulb to light up, but nothing with the adjustable gap unit or grounding the plug. Thanks for you help. I'll keep looking.
 
So this is the Golden Jubilee Edition. I have the very same motor....runs perfect love it. Tiller had broken off at main bracket....welded it. This is a great motor. New condensers then too?
 
Plug wires screw into the coils.----Condensers will often test good on a MERC-O-TRONIC magneto analyzer machine.------Then when you put them out in the sun for 1./2 hr ( heat soak ) they fail the exact same testing.---Not only that condensers are cheap compared to jumping up and down with the ----" why is it hard to start " ---- disease /syndrome.
 
Excellent information. Condensers/capacitors are at times heat sensitive, our OP has not replaced them that I see. I don't trust an "ohm test" on condensers. They have to be charged with a spark, then left alone a few seconds, then discharged by hovering it's wire over the outer shell. A significant arc most be observed. I charge my condensers with an old oil burning furnace transformer. Not too strong, but just the right voltage/amperage. Never blown a condenser in 50 years. If anyone's listening or interested, I can post a picture......but I'm from the "old school".....don't replace what is still good.
 
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Anyway I took some time off working on my no spark problem. Today, took it apart, AGAIN, looking for anything I might have done wrong. A random brain burp "what if I hooked the green coil wire to the wrong set of points?" Checked the picture in the manual and sure enough that is what I did. Note to self: Don't take motor apart one year and try to reassemble the next year from memory (especially at my age). Thanks all of you for your help. I learned a lot.
 
The ring is a " shop time saver "------The job can be done without it.-----leroysramblings----Is one place to learn about the wonderful magneto on your motor !
 
timguy said:
...but I'm from the "old school".....don't replace what is still good.
Click to expand...

I agree, that is if it was made this century but when your tuning outboard motors that are 40, 50 and 60 years old why not replace all that old electrical crap while you have it apart? It's not like it cost a fortune. Who wants to keep going back and replacing ancient parts as they fail one piece at a time?
 
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