Reply To: Johnson 6: No spark on both cylinders

[David Stanton]

You mentioned fuel on the plugs. Did you assume there was no spark? or did you clean up the plugs and check for spark in the plug gap with them removed and touching metal,or checked for spark by some other means? The trip could have caused residual fuel in the crankcase to work it’s way through open ports or past the rings to the plugs, and a plug wet with fuel will not spark, as the spark current finds a conductive path from the electrode tip , down the tip’s insulator to the base metal. This is more likely to happen if it was stored or rode with the spark plugs pointing toward the ground , so gravity moved fuel to the lowest point in the cylinder, being the spark plugs. If you did not run the gas out of the carb before traveling, and the motor was on top of the car with spark plugs down, the carb could have emptied into the crankcase with road vibration making this more likely.
Dave