loosing spark same cylinder

[jeff6898]

1979 Evinrude 85 hp 85999R

THe same cylinder bottom left keeps loosing spark or getting very weak spark. 4th new coil on this same cylinder. Works great for a little bit then after a long run engine starts running crappy. Test spark and none or weak just that one. Same sympton past 4 times. Any ideas? all these items are recently new.

2 power packs
4 coils 7 total if you count the times I replaced the bottom left
4 new wires
4 new plugs
fuel pump
carbs rebuilt
new fuel lines

 

[Sherman]

Re: loosing spark same cylinder

On my 79 115 I fought a problem like this that turned out to be a broken wire in the trigger assembly. These wires flex every time you move the throttle and over time come apart a little at a time. I bought a used one on ebay and it has worked great for three years.
Sherm