63 Johnson 18 hp ignition mystery

[AlTn]

check the underside of the flywheel in the area of the magnets as well as the heels of the coils...see any evidence that they could be coming into contact with one another?...

 

[restornator]

this is useless without pics. And what good is having spark when the cylinder head is off?

 

[twocyclemania]

Magnets clear of touching the flywheel. As for the pic's; I don't know what they would tell you other than it's a picture of a standard mag plate with the coils, condensers, etc. It's not like it's a mystery system or trying to figure out a mystery motor year/model. Cylinder head is off because the head gasket needs to be replaced. I don't intend to replace the head gasket if I can't get ignition. Actually, it makes spinning the motor over easier. Is there something I'm missing about the relationship of the head being mounted with the electrical system problem?

 

[HighTrim]

While the grease on the crank is a no no (absolutely clean, with acetone, before installing flywheel) that was not your issue. Nor is the missing head.

I would almost be willing to bet money the issue is still with your points not being clean. I know, they are new. That means nothing really. I dress even brand new points before installing. If you don't have a points file, wrap wet/dry around a hacksaw blade, and run that through many times. Blow off with compressed air. then dip paper in acetone and run that through to clean, after setting at 020.

Or I have had brand new, aftermarket points fail upon installation. Rare but happens.

Or perhaps the condensors are bad?

The picture request is not totally crazy. Im sure you know what you are doing, but we have had fellows on here that ended up having the points leads going to wrong coils for example. Would never have caught it without a picture.

 

[restornator]

Didn't install the ignition wires correctly the first time. You have to remove the magneto plate in order to install those wires. I bet they're slipping out as soon as the temperature drops.

 

[twocyclemania]

Well I think it's time to eat crow. I hate to admit it but I found the problem; really basic. As embarrassed as I am to admit it I believe that all those out there with the helpful suggestions and expertise deserve an answer; even at my expense. It's also something to keep in memory when someone else runs into an ignition problem. I adjusted the points back (reduced the gap); visually they looked close. As soon as I reduced the gaps I got good spark to both cylinders. I don't know what they were but I would estimate about .25. What a difference a few thousandths makes. I should go 'before the mast' and be reduced in rank for overlooking this most basic checkpoint. Thanks again everyone.

 

[racerone]

I preach using a meter and the timing marks on the magplate and flywheel to set points for maximum spark.--------It seems very few folks understand how critical it is for points to open at the correct time.

 

[tomhath]

I don't know what they were but I would estimate about .25. What a difference a few thousandths makes.

It would be interesting to measure how many degrees sooner the points open at .025 versus .020. Obviously early enough that the coil wasn't in the magnetic field.

 

[nwcove]

im gunna razz the op a bit......how the heck can you visually estimate point gap when yer dealing with thousands of an inch??

 

[bwkre]

Probably a good thing that motor is not all together. Timing by eye can be costly. As the heel of the point wear from contact with the cam, the timing will change. The points will open slightly later as the heel approaches the cam high spot.This also happens when the points have too small a gap. That means a later or retarded spark and because it does not occur at the height of the collapsing magnetic field, the spark will be weaker. As a result, starting is harder and the motor will lack power. Not so bad until it wears far enough for no spark.

But having a larger gap than intended can create bigger problems. An excessive gap can open the points way before intended and there could be no spark. That would be good, and probably would save your motor. If the points are set too wide and it creates a spark, the timing will be advanced. That can cause pre-ignition which will lead to a piston meltdown. The fire occurs too soon, too hot, and melts the piston.

Sorta glad you don't have it running yet. It pays not to play with manufacture setting. 20 thou is 20 thou.