Johnson AD-12 mystery

[63lstrition]

Here are some addtl pics. The first pics show the flywheel being turned 90 degrees at a time

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[david-bartlett]

Looking close at your pictures, you can see where the flywheel is dragging on the magneto plate. As you have likely already decided, I think the flywheel is the problem.

There are several on the internet ePay site right now. Part # 580217

Good luck.

[aquasonic]

There is very little clearance for the ignition component wires. In one of the pictures, there is a bright green wire from the good coil to the points. That wire needs to be routed underneath so it doesn’t rub on the flywheel hub. It looks as though it may just be starting to rub?

Improvise-Adapt-Overcome

[wedgie]

I have a few extra flywheels. Where you at 63lstriton? .

In one of your pics it looks like someone has been prying on the mag plate and bent it.

[wedgie]

Also, what’s up with the throttle lever ? It may be an optical illusion ,but in your pics it looks to be broken off. Here’s a pic of a 5.5 , but your 7.5 is the same.

[63lstrition]

Yeah, she broke the throttle lever. That is on the parts list.

Located in Green Bay, Wisconsin

[aquasonic]

I took another look at the pictures. I notice that the two long screws that attach the coils to the armature plate base are missing. These two screws, along with two short screws on the plate itself are all that holds the armature plate down to the base. I am wondering now if the plate is not seated properly and is causing the contact with the flywheel?

Improvise-Adapt-Overcome

[wedgie]

quote 63LSTriton:

Yeah, she broke the throttle lever. That is on the parts list.

Located in Green Bay, Wisconsin

Wisconsin ! you should have no trouble finding parts close to you.

[fleetwin]

Well, the brass ring and retainer seem to be correctly oriented. The crank does not appear to be galled from aluminum transfer either. I would start with trying a different flywheel, which is the easiest place to start.
Someone raised a good point about the missing fasteners, perhaps the mag plate is just being drawn upward because it is loose. I realize the screws are missing because you pulled it apart for pictures. Nonetheless, reinstall the fasteners, then try lifting up/down on the mag plate to see if it is loose for some reason. And, it is surely possible that someone pried up under the mag plate while trying to remove the flywheel in the past, which may have bent it.
And yes, once the clearance issue has been resolved, that ignition system looks to be in tough shape.

[crosbyman]

crooked flywheel notwithstanding ….

anyway a spacer washer under or over the cam lobe would help lift the flywheel enough to clear the mag plate….?

i know it is not design intent but…. if it solves the problem without affecting the rub blocks on the point arms…

all that seems needed here is 1/16 or 3/32 spacing to clear the mag plate if no cure is found for this mysterious problem

Joining AOMCI has priviledges 🙂

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