OK the problem is the engine surges at WOT. No problems at idle or any other speed until I reach almost full throttle. Also it doesn't do it all the time. I have had the carbs cleaned and rebuilt gas tank fuel line and fuel filter have all been replaced. My next step is the fuel pump. It is still the VRO pump with the oil side bypassed and it is original from 1985. I have read where other problems can cause this so I would like some input.