74 Evinrude 9.9 no spark

[PW2]

I've been working off and on on this motor, and now I can't seem to get any spark.

I've pulled the flywheel and there are no obvious issues. The points seem to be opening to the proper gap, the coil and condensers "look" to be ok...is there a simple test for these components?

My big concern is the two coils at the spark plug end. The plug wires fell out of the coils while I had the motor apart, and I tried to guess at which coil went to which cylinder--I thought I was right, but now not so sure, and I can't trace the wires by sight with the flywheel off. Is there an easy way to tell which it which? I'm also not sure if I got the plug wires securely screwed back into the coils. They don't seem to want to screw in easily. Is there some sort of trick to this, and assuming this is a right handed screw in the coil to affix the wire, does that mean the wire should be turned counter clockwise in the coil to tighten?

The coils themselves "look" to be ok, although not sure how they'd look if they were bad...

 

[Xcusme]

Re: 74 Evinrude 9.9 no spark

OK, I'll give this a try...
First, are you getting any spark from either plug wire? Stick a phillips screw driver into a plug boot, hold shaft of screw driver 3/8 to 7/16 from the power head and pull starter rope. Get any spark?? Test both plug wires.
If you don't have spark from either wire there's a couple of things to check. As you mentioned, if the plug wires are not screwed into the coils, you'll loose spark to the plug end. The wires screw into the coils in a clockwise direction, just like you were screwing in a screw. I'll assume you're using 7mm solid core wire and NOT automotive type ignition wires. I'll also assume that you have the plug boot end metal coiled clips installed with the sharp spike into the plug wire.
You say the points are properly adjusted...are they really? Remove flywheel, rotate crank shaft until crank shaft key way aligns with the rub block of the points (the rub block contacts the points cam). Adjust point gap for .020.
Rotate crank shaft 180 degrees to other point set and again, align crank shaft key way to points rub block. Adjust the second point set gap to .020.

Just to check your work, pick one of the coils, that coil's matching point set is counter clockwise from that coil. If you have a coil connected to the wrong point set, things won't work. If memory serves the front most coil goes to the top cylinder.

While you have the coils off, make sure the plug wires are fully screwed into the coils (use a bit of silicone grease on the outside of the plug wire to help screw them in). Slide the little rubber boots up the plug wire and seat on the coil. Remount the coils with their bases on the mounting boss so that both surfaces are flush. You have good spark on both plug wires. BTW, bad coils usually, but not always, shows signs of cracking on the outer surfaces and should be replaced.

 

[CATransplant]

Re: 74 Evinrude 9.9 no spark

If your plug wires are coming out of the coils, then they weren't in correctly in the first place. You need wire plug wires, not resistor wires. I don't know your particular engine, but they have to be fully inserted in the coil. That often means some twisting.

If you have no spark at all, make absolutely certain that your lanyard or kill switch, if equipped, is functioning properly. That's a more common problem than folks think.

 

[PW2]

Re: 74 Evinrude 9.9 no spark

Thanks. I got this motor as a project motor from a person who could not get it to start. Not exactly sure what they did to try to get it to start, but it had low compression and evidence of water leaking into the lower cylinder (steam cleaned appearance). I fixed that, but everything is suspect as when I got it, the fuel pump was in 20 pieces in a ziploc bag. (I replaced it with a whole new unit)

It doesn't have a lanyard, but it does have a push button kill switch, which the normal position should be ok. It appears to be operating properly. I will check it with a continuity tester.

I'm reasonably convinced the plug wires, and their attachment to the coils are in fact the problem. I assumed they were the proper wires, but it's certainly possible they aren't. I've never had to replace one before on any other motor I've had.

Thankfully, this is not a motor I rely on to get out fishing!

 

[PW2]

Re: 74 Evinrude 9.9 no spark

Ok, now I'm getting frustrated. I must be missing something!

Replaced both coils, purchased new with spark plug wires attached. Even made a spark tester, as I thought maybe I couldn't see the arc at the plugs. Nope, no hint of a spark at either plug lead.

Motor has a push button kill switch. Not exactly sure how it works, but it has two leads, one that goes to each cylinder. Thought it probably worked by grounding out each cylinder. I checked with a continuity tester, putting one lead on the wire leading from the switch, and the other test lead to ground. No continuity from either wire leading from the switch to ground.

I checked the switch by connecting one test lead to each wire from the switch. When button depressed, continuity established. when button released, continuity broken. It appears that the switch is working.

I've checked every concievable ground connection, and everywhere checks ok, from anywhere on the engine to anywhere else, even on the motor housing.

This is a points and magneto ignition, and I know they are pretty simple. I had the flywheel off, and I checked and reset the points, and replaced the flywheel.

I can take the flywheel off again, and check the points again...Is there a test that I can perform on the condensers and primary coil with my multi purpose electrical tester?

Any other ideas, or anything you can think of that I can check?

 

[reload]

Re: 74 Evinrude 9.9 no spark

Condensers can be checked with a ohm meter. Should show a very high resistance or open. Depending on the meter sometimes you can see them charge. Shorted condensers would cause a no spark condition. It would be extremely unusual for two to go at the same time. I've only two bad ones in my life.

 

[PW2]

Re: 74 Evinrude 9.9 no spark

The condensers "look" fine. Since I'm not getting any spark out of either of the spark leads, I kind of ruled them out, as I kind of wanted not to keep replacing things on the chance I might find the problem.

Is there a test for the primary coil under the flywheel?

Does that kill switch sound like it's working properly, or is there some test that I should have performed that I didn't?

 

[Xcusme]

Re: 74 Evinrude 9.9 no spark

Did you make sure the coils are properly indexed to the armature plate? The coils should be positioned so that their bases are flush with the mounting boss 's. Surface A should be flush with surface B.

The tests you made to the kill circuit were done correctly. Both kill wires should have no connection to ground, on either leg. You should show open circuit between the 2 wires until you push the stop button. You should then show a dead short. The kill circuit works by grounding each set of points through the other set of points.

 

[PW2]

Re: 74 Evinrude 9.9 no spark

Thanks, I'll pull the flywheel again and check that tonite. I'll even post some pictures of it if it seems appropriate.

This simply can't be that mysterious in a simple magneto ignition system.

 

[mikesea]

Re: 74 Evinrude 9.9 no spark

disconnect the kill button completly,then check for spark,be sure the kill wires arent being pinched somewhere,slightest leak of ground will kill the spark

 

[lexkyboater]

Re: 74 Evinrude 9.9 no spark

The new OMC coils I bought for my 1971 9.5 HP had a secondary resistance of 92,800 and 93,800 ohms (green wire to the plug wire stinger). Primary resistance should be around 0.9 to 1.0 ohms (green to black wire).

 

[PW2]

Re: 74 Evinrude 9.9 no spark

Ok, on further review, the coil under the flywheel looks discolored and appears to have leaked some reddish-brownish substance around the windings, with the core blackened a bit. The color (that appears green on your photo) is severely blackened on mine on one end...the other end is ok. The surface of the coil is very close, but not quite flush with the index per your photo. It would be difficult, although possible I suppose, to get it closer. Is there a test for proper functioning of this coil?

I would post a photo if I could figure out how to resize them to within forum size limits

Thanks

 

[Xcusme]

Re: 74 Evinrude 9.9 no spark

If that coil is leaking anything, it's toast. Plan on replacing both coils, they're cheap. Replacing the point sets and condensers certainly couldn't hurt and you'll have a fresh ignition system.

BTW, you have a PM.....