Causes of power pack failure

Chevyls6

Petty Officer 1st Class
Joined
Oct 11, 2019
Messages
242
What causes the power pack to go bad on cdi engines ? I believe mine is fried but I don't want the new one to suffer the same fate.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,552
What motor ??----What testing have you done to determine it is " fried " ?----Many powerpacks are replaced with the owner then reporting ---" still behaves the same "
 

Chevyls6

Petty Officer 1st Class
Joined
Oct 11, 2019
Messages
242
Symptom is spark on top cylinder only. Stator and timer base are sending the correct voltages to the power pack. Engine is 1977 55hp
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,471
Swap coils and if still only sparking on top cylinder, then CDI is bad. They can fail for no apparent reason. I’ve replaced 10+ CDI boxes for customers this year alone. Seems like 75% are total failure, 25% lose spark on one cylinder like yours.
 

Chevyls6

Petty Officer 1st Class
Joined
Oct 11, 2019
Messages
242
Swap coils and if still only sparking on top cylinder, then CDI is bad. They can fail for no apparent reason. I’ve replaced 10+ CDI boxes for customers this year alone. Seems like 75% are total failure, 25% lose spark on one cylinder like yours.

Thanks for the info. I already tried swapping the coil primary wires on the power pack and the condition remained the same. kill switch wire did read about .25v as well if that makes any difference for its longevity.
 

Chevyls6

Petty Officer 1st Class
Joined
Oct 11, 2019
Messages
242
Bad coil.

Dang you're right haha. I can't believe I missed that. If the top coil was on the working bottom cylinder switching circuit it should have sparked. Guess I'm gonna go to cdi electronics and ask for a new coil since I just bought it.
 

Chevyls6

Petty Officer 1st Class
Joined
Oct 11, 2019
Messages
242
CDI electronics is replacing the coil without a fight. Their customer service is excellent.
 
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