1979 Johnson 115 testing the coils

TampaBoater

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Feb 23, 2012
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I have a 1979 Johnson 115 sea horse with no spark on top port cyl. I have replaced stator, timer base, and have ruled out power pack issue. Rectifier seems to be alright I get readings one way but not the other. I figure its got to be a coil. Its the kind that comes with the spark plug lead all built in. Other than replacing the coil, can I do something to test it besides swapping it with the bottom coil? I don't want to do that because I would have to re order the connector pins. Can I test it for ohms? Would I even get a reading? I have already taken he coil off the motor? How should I connect the test leads on the multimeter?
Any help greatly appreciated.
 

emdsapmgr

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Dec 9, 2005
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There are some excellent ignition troubleshooting tips in the guide on this website: cdielectronics.com. The coils are usually pretty reliable. Generally considered the most reliable of all the ignition components. I'd probably do another test first. Swap the two matching power packs. See if the top port cyl is still not firing after the swap.
 

TampaBoater

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Feb 23, 2012
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There are some excellent ignition troubleshooting tips in the guide on this website: cdielectronics.com. The coils are usually pretty reliable. Generally considered the most reliable of all the ignition components. I'd probably do another test first. Swap the two matching power packs. See if the top port cyl is still not firing after the swap.
Emdsapmgr.. as i said i ruled out power pack issue by swapping them. Still no spark.
 

schematic

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Can I test it for ohms? Would I even get a reading? I have already taken he coil off the motor? How should I connect the test leads on the multimeter?
Any help greatly appreciated.

compare the coil readings from a known working one. sometimes a bad coil will not show bad on a ohm test. swapping is the best approach
 

emdsapmgr

Supreme Mariner
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Messages
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Have you read thru the CDI guide? Referencing the CDI troubleshooting guide, they agree that swapping coils is the best way to diagnose a problem coil.
 

TampaBoater

Petty Officer 1st Class
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Have you read thru the CDI guide? Referencing the CDI troubleshooting guide, they agree that swapping coils is the best way to diagnose a problem coil.


Yes i did last night. I suppose I got no choice but to swap them.
 
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