Evinrude 25202r no spark

Rjybilcom

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it measures the coil resitance, plug wire and plug booth pin contact for proper continity.
Just out of curiosity what sparkplug should I be using? When I bought it, it had C6J lawnmower plugs in it. Everything I've read says J4C.
 

Rjybilcom

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post the resistance values as measured from plug boots to engine frame .

look for a steady ohms value 3-8 kohms approx while moving the throttle from idle to high speed .
Reading an average of 6.13 on the bottom, OL on the too, yet that's the one that flashes the strongest with the inline tester.
 

Crosbyman

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IMHO... this is a standard magneto and both coils should show a reading from plug boot to coil secondary to ground.... somewhere from 3-8 kohms depending on manufacturer.

could bad coil, bad HV connection (corroded) bad pin prick in the boot open plug wire due to flexing etc...
 

Rjybilcom

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post the resistance values as measured from plug boots to engine frame .

look for a steady ohms value 3-8 kohms approx while moving the throttle from idle to high speed
IMHO... this is a standard magneto and both coils should show a reading from plug boot to coil secondary to ground.... somewhere from 3-8 kohms depending on manufacturer.

could bad coil, bad HV connection (corroded) bad pin prick in the boot open plug wire due to flexing etc...
 

Rjybilcom

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Keep in mind I've never worked on an outboard motor, what is the coil secondary and the HV connection? I know enough about electronics that if you can measure resistance on one spark plug boot and none on the other, you have an open somewhere.
 

Crosbyman

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the hv connection is the point of connection of the plug wire into the coil. today's coils have a screw pin where the 7mm plug wire is actually screwed on the pin. old coils had simple needle like pins. it is very important no to use automotive CARBON fiber wires.....

use only solid strand copper wire as frequently used on mowers, bikes etc... where RF noise is not critical.

to access it you will eventually need to remove the mag plate where both coils sit and the HV wires exits underneath . see video at minute 16:50
utubes galore on servicing OMC magnetos
look above at the at the diagram above showing potential trouble spots
 
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Crosbyman

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see pics where you "screw in" the HV plug wire and info from the JOhnson service manual on oldies from late 40s to late 60'S .... same old magnetos like your's
 

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Rjybilcom

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see pics where you "screw in" the HV plug wire and info from the JOhnson service manual on oldies from late 40s to late 60'S .... same old magnetos like your's
Seeing these photos start to make sense. I measured resistance of both coils from the ground lead of the coil to the lead going to the points and condenser and got .7 on each, does this mean both coils are good? So I may have a break in the HV wire, which is basically a spark plug wire? I have a golf cart where the plug wire connects to the coil the same way.
 

Crosbyman

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both short primaries wires will give you 1 or less ohms either one measured with the HV pin should give you near identical readings ( 3-8 kohms approx.)


see TEST NEW COILS section.....in this link to servicing similar magneto on a 3hp

 
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racerone

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???-----Your local boat shop will have a roll of proper wire.---An every day simple item.-----Needs to be 7mm with wire core.------That magneto is elegantly simple to repair / maintain / cheap parts too.----Visit -----leroysramblings-----for all you need to know !
 

Rjybilcom

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???-----Your local boat shop will have a roll of proper wire.---An every day simple item.-----Needs to be 7mm with wire core.------That magneto is elegantly simple to repair / maintain / cheap parts too.----Visit -----leroysramblings-----for all you need to know !
Whereas most automotive has the carbon fiber core?
 

racerone

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Correct.-----I have a bunch ( 40 feet ) of the wire core stuff on hand for my projects.------Boat dealer had it in stock.-----This simple magneto was first installed in about 1950 and was installed till about 1990 on some motors.---Used on 1.5 / 3 / 5.5 /7.5 / 10 / 18 / 20 / 25 / 28 / 30 / 35 / 40 HP motors.-----A simple / elegant and reliable set up.-----But it requires that owner needs to understand the fundamentals of how it works.
 

Rjybilcom

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Correct.-----I have a bunch ( 40 feet ) of the wire core stuff on hand for my projects.------Boat dealer had it in stock.-----This simple magneto was first installed in about 1950 and was installed till about 1990 on some motors.---Used on 1.5 / 3 / 5.5 /7.5 / 10 / 18 / 20 / 25 / 28 / 30 / 35 / 40 HP motors.-----A simple / elegant and reliable set up.-----But it requires that owner needs to understand the fundamentals of how it works.
I've serviced copiers and printers for 26 years, before that photo lab equipment. I can work on my F150 and Explorer, even riding mower. Outboard motor is a brand new experience but I'm learning as I go along. I appreciate all the help I get from this forum.
 
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