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Magneto wire

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Seahorse50

New member
I have a 59 Johnson fat 50 model v4s-11.
the wire the comes off the magneto down to the distributor then into the harness. Should this wire have 12v going to it when key on?

Dont seem to to have a spark, and just trying to get a better understanding of this system before I get messing with it much.
 
Disconnect the wire at the distributor and you should have spark on all four plug wires. To kill the motor you short that wire to engine ground. If you applied battery pos to the distributor you need to get a new coil in the driver assy. May as well replace the two sets of points and condenser. There are two M terminals on the ignition switch one goes to ground and the other goes to the magneto.
 
Nope didn't apply 12v to the magneto, just wondered if it should have
12v to it.

so to eliminate a bad switch unhook the wire and try it?
if still no spark, that would mean timing issue or bad magneto, coil?
All those can be tested with a ohm meter correct? If so what should the readings be?
 
Clean and adjust the points first. Use rubbing alcohol or acetone to clean the feeler guage and points. Sometimes a bad condenser will cause a no start condition. If you know the points and condenser are good and you still get a no spark condition the coil is likely the suspect. A ohms test of the coil can be deceiving if it a internal short no real way other than a spark gap test with a open air spark gap tester. There can also be a internal crack in the cap or rotor diverting the spark from the plug wires. Start with the cheap parts points and condenser first you may need to sell your first born for a new coil, cap or rotor. Never apply battery + to the magneto for even a split second.
 
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