Thought I had a fuel problem but not. Yellow spark on middle cylinder. Have not had time to test. Would it be more likely a bad coil or could this be a CDI problem. Idles fine, starts right up. Will not run above 5000 RPM without breaking up.( Actually it will go up to 5600 or so then start to surge, finally settling down to about 4500 RPM) Had all the symptoms of fuel starvation but tested everything fuel lines ball connections, even replaced the fuel pump and rebuilt the carbs. Appreciate your replies.
