1954 johnson seahorse 10 magneto and flywheel issues

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guy9023

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Jul 1, 2012
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i replaced the original plug wires from the coils to the spark plugs and now it seems the flywheel is scrubbing against the edges of the coils, more noticable at low throttle where the engine will shake and stall out, was running fine before so i know its not a carburator issue or such, when i remove the flywheel you can see scrub marks against the outer edge of coils and inside the flywheel on magnetic plate. has anyone else had this issue? i also have the coils adjusted as far in on towards the crankshaft as they will go, please help if anyone has an answer i thankyou in advance:confused:confused:
 
kfa4303

kfa4303

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Re: 1954 johnson seahorse 10 magneto and flywheel issues

HI guy. Welcome to iboats. Your flywheel should not be scrapping against the coils under any conditions. You'll need to remove the flywheel and loosen the screws that hold the coils to the armature plate and gently squeeze them towards the center. You'll only need to move it 1/8"-1/16" at which point you can tighten the screws back down. Simply repeat for the second coil. If the coils won't budge inward any, they are probably pinching a wire somewhere which is, in turn preventing the coil from being able t move. Here are some handy links with lots of pics that may e of some use too.

http://www.leeroysramblings.com/johnson_QD.htm

http://www.outboard-boat-motor-repa...on 3 HP 1952-1967 Ignition System Tune-up.htm
 
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guy9023

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Re: 1954 johnson seahorse 10 magneto and flywheel issues

wow! greats links! thanks a ton, i will have to pull the flywheel again and see if i can squeeze those coils together a bit closer. hopefully the rain quits and i can get to work soon :)
 
F

F_R

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Jul 7, 2006
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28,195
Re: 1954 johnson seahorse 10 magneto and flywheel issues

The ends of the coil's laminated cores are supposed to be flush with the machined edge of the armature plate where they are mounted. Too far in and you will have poor spark. Too far out and they will rub on the magnets.

If they are flush and still rub, there is another problem. Loose bearings on the crankshaft or wobbly armature plate are the usual culprits. Wobbly armature plate can be because it is broken, or worn out, or the mounting rings are worn out or the aluminum one is upside down. It goes flat side up.
 
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