50hp johnson top cylinder dead

[captainadventure]

Ok geniuses, I have a johnson 50esl71s that I rebuilt two years ago. Ran it about 50 hrs untill it dropped top cylinder. Excellent spark both coils, compression 155 both cylinders. Upper plug wet with fuel. Idles good, pull lower plug wire engine dies. New reeds, cylinder head gasket, trigger and stator.

 

[racerone]

Fuel pump is broken I think.

 

[captainadventure]

Fuel pump is broken I think.

New pump

 

[captainadventure]

Top plug fuel soaked

 

[racerone]

I guess I missed the " new fuel pump " in post #1----Sorry.

 

[captainadventure]

I guess I missed the " new fuel pump " in post #1----Sorry.

 

[captainadventure]

I have researched these loop charged engines and it seems this is a recurring problem. I have not however seen a resolution. Overload of fuel in the cylinder indicates no fire but I have proved out the ignition system and I am not easily stumped but this one has me baffeled.