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1975 Johnson 50ESL 75B electrical readings

B

bootss

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Hello all,
My problem is top cylinder does not have spark.I have replaced Power pack and top cyl. coil.Pulled flywheel the stator is clean, no burn marks,trigger looks good.
My question is: What voltage should i see from power pack to coil terminal while cranking engine.This is a screw terminal power pack.Test light shows a trigger "spike" while cranking,but i am starting to think the voltage is too low to fire a plug under compression.By the way the engine has 125# on both cylinders,thanks for an info.
 
Rwbutler said:
Their is a CDI electrs troubleshooting guide available on the home page of this site that may help you.
Click to expand...

I did as it suggested in troubleshooter and reversed the coil leads at the power pack.The motor just backfired and did not try to start.I put them back and then reversed the trigger wires,same thing backfired,no try to start.Put everything back and motor runs fine on bottom cylinder only,no backfire or spark out of the top cylinder.Again i'll ask can someone give me a voltage at the power pack with coil wire disconnected and cranking engine?
 
If you would look and read the above mentioned CDI troubleshooting guide,it will give you the info you reguire.
Have you done anything recommend your earlier post?
 
If i could find the guide i'd read it.It's not on the homepage on my computer.Sorry if i asked too difficult a question.
 
Highly doubt he's got a M80/S80 in his possession...there is a bad YouTube vid out there where guy shows you can check with 12 volt test light..
To test …
1) remove spark lead and attach to a open air gap tester.
2) crank motor and see if both are sparking..if both have sharp blue snapping spark you have mechanical problem
3) If still only spark on bottom swap trigger leads, if spark still stays on bottom the pack is defective
 
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