'59 Johnson 18 Acting Up Again

[Rick K]

Hi all,

My last few posts dealt with no spark to the lower cylinder, replacing the coil, etc., to get her going again. Thanks to all again who helped out.

Well, she started acting up again. I pulled the flywheel, checked everything out, and found a cracked cam lobe. This would indicate an over-tourqe on the flywheel. I've always torqued it to 40, but who knows what my uncles did...

I pulled the stator, and there appears to be some wear tracks in the bottom, i.e., it's rubbing on something. Actually, you can hear it rubbing when it's running in the can.

Since this obviously isn't right - and most likely the cause of some of my problems, can somebody tell me if it's usually the taper in the flywheel that goes bad, or the taper in the crank that's worn?

I will attempt a repair on her one more time - if no go, then somebody's gonna get a lot of nice parts.

Thanks!
Rick

 

[Paul Moir]

Re: '59 Johnson 18 Acting Up Again

Normally the flywheel taper will stretch or crack. I've never heard of a crankshaft taper wearing out. Also, you may be in for a new set of points if the rubbing blocks on the ones you have got wrecked.

Does the stator plate very loose? Can you wobble it until it drags on something? That shouldn't have anything to do with the cracked cam, but it's easily fixed.

 

[Rick K]

Re: '59 Johnson 18 Acting Up Again

Thanks Paul. All those parts were just replaced (I know, that's meaningless...), and the motor ran great for a total of about 3 hours. I also failed to mention that one of the new coils I put on has got rub-wear right on the front edge (not the part that faces out) but towards the inside, on the top. So, something's worn.

The bottom of the stator is definately worn, and, the round brass support definately looks as if it's got some wear on it as well.

If I replace that flywheel, and perhaps the support, do you think I can get away without changing the stator plate?

Thanks
Rick

 

[Paul Moir]

Re: '59 Johnson 18 Acting Up Again

No trouble. If the coils ended up rubbing I think you've got a very wobbly armature (stator) plate. This cheap simple fix, courtesy of Joe Reeves will help:

(Magneto Armature Plate)
(J. Reeves)

If the armature plate has a a loose fitting, wobbling motion (the plate that the points, coils etc are attached to), it is usually caused by a slightly worn support ring. This allows the point setting to change erratically as the armature plate turns.

The cure is to remove the armature plate so that the support which is attached to the powerhead with 4 screws is visible. Then, with a screwdriver and hammer, or some tool of your choosing, and looking straight down at the support ring, make an indentation at what would be called the 12, 3, 6, and 9 O'clock positions. Install the armature plate and check for a smooth turning wobble free movement.

You may need to do that procedure a few times to obtain the proper fit (not too tight, not too loose), but it's worth the effort.

If it's really wobbly, it can be worth slipping a thin piece of shim stock between the armature plate's inside bearing and the block to further reduce the slack. Reducing the wobble will make the engine run much quieter, and the timing will be far more accurate so it's worth doing even on engines that don't have excessive wobble.

If the rubbing blocks on the points are fine, then they can be re-used no problem. I was worried about the crack in the cam massacring them.

 

[Rick K]

Re: '59 Johnson 18 Acting Up Again

Paul - Thanks again. I saw that post last nite, and printed it, along with a few other posts. Haven't had the time to read 'em completely though.

Just by reading this, the problem becomes blatently apparent. The support ring is so worn, that I could probably pull that inner ring thru it with no trouble.

Looks like I'm on the parts hunt...

Thanks again Paul - now I have a new project!!!!

Rick