QD19 spark.. It’s alive I tell you, ALIVE!

[beerman57]

Sure would like to run this rebuilt P/H – new everything & conn. rods updated to bearings. NO spark on #2 cyl. – switched condensers…same, tested coils …36,000ohms and .7ohms, cleaned the points… infinity open & .1ohm closed. Tried to convince myself that a plug wire or kill switch wire was grounding, but no continuity between wires, mag plate, anything at all. And low OHM from plug wire end to end, good values with the coils installed. I’m about stumped, going to switch the coils around Sunday, then the points, to see if I can get the spark to move to #2 cyl. What else could I possibly be missing? Oh yeah, I’ve tried with the kill switch disconnected, wires not grounded, too.

[mercuryman]

You have checked everything but spark plugs.

[chris-p]

Did you try polishing points, then cleaning with paper dipped in acetone?

[legendre]

If everything you’ve stated is correct, then the list is fairly short.

Are you certain that the plug wire for the ‘bad’ cylinder isn’t leaking off to ground? Perhaps it has broken insulation, or has been punched-through by high voltage? Simple continuity tests would likely never reveal these issues.. they may only manifest when the voltage reaches the gap-jumping level.

[beerman57]

legendre,
could be, had the same problem with a ’62’ Evinrude 10hp recently but it’s plug wire showed continuity to the mag plate.
I’m satisfied the points are clean, using a spark checker – not grounding the plugs, I should probably close the gap on it some, it’s probably over 3/8".
By the way, I’ve had 2 people recently say they have no spark, sticking a screwdriver in the plug lead and holding it close to the block, both had good spark using spark checker and had fuel problems keeping their motors from running.

Is the 3.6K ohms considered low? Should it be around 7K ohms? I have big, bright spark – jumping a pretty big gap on #1 cyl. But then again, one thing seems strange, I never get a spark till the 2nd or 3rd pull on the starter rope. I HATE SPARK PROBLEMS!!!

[chris-p]

All coils are different. They can be anywhere from 3000 to 8000 ohms.

When I find it takes a few pulls to get spark, usually indicative of dirty points. Even finger print on them will do that.

I polish them to a high shine, then dip business card stock in acetone and run that through. Then blow off with compressed air.

new points out of the package sometimes need polishing, as they have a haze on them.

[beerman57]

I used a points file and thin rag with acetone, I can try some fine sandpaper and more acetone but #1 points are OK.
Those 2 people who thought they didn’t have spark – one had a bad Oring in his single hose fuel connector, acts like the primer bulb is no good.
But get this, the 2nd one is a friend who got a nice 20′ center console W/ 1998 Johnson 200 W/ dual axle alum. trailer for $2000. It had been sitting so I did the carbs, impeller & L/U oil. Last Saturday we went 25 miles out in the Gulf, the moon set about 11AM and it was like turning on a light switch – went from bait sitting on the bottom with a snapper nibbling on it one minute, the next minute you couldn’t get a bait to the bottom before a 13-15lb. Red Grouper would be on your hook. By noon the 4 of us had our limit, we called our friends in another boat over so they could fish the spot and we headed in. I’ve been eating fish almost every night and have some in the freezer too. Ever had the cheeks from a grouper? 2” – 3” in diameter and melt in your mouth.

[legendre]

quote Chris_P:

All coils are different. They can be anywhere from 3000 to 8000 ohms.

Absolutely. One coil’s secondary winding may have more / fewer turns of smaller / larger-gauge wire than another, and still achieve the same basic results. Resistances can vary widely between otherwise similar designs – and temperature also plays a role.

Of course, if you have two ‘identical’ coils, they should measure within a few percent of one another – and really, that’s about your best guide, unless the mfr. is so kind as to provide resistance tables.

[legendre]

quote beerman57:

legendre,
could be, had the same problem with a ’62’ Evinrude 10hp recently but it’s plug wire showed continuity to the mag plate.

Ha! We should all be so lucky.. many plug wire troubles tend to be more subtle than that.

quote :

But then again, one thing seems strange, I never get a spark till the 2nd or 3rd pull on the starter rope.

That’s definitely not right.. and it’s a clue.

quote :

I HATE SPARK PROBLEMS!!!

Battery & coil systems are fine. Flywheel magnetos can be a pain, particularly when you don’t have a shelf full of known-good replacement parts.

[frankr]

About those plug wires: Are they new, or old ones? If old ones, check for a pin hole where they are clamped to the mag plate. A spark will arc through that pin hole, but the low voltage of an ohm meter won’t and it won’t show as a short to ground. Seen it lots of times.

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