Ok, since my last post I found I had a blown head gasket, fixed it. Had a bad ignition coil, fixed it too. Bad ignition switch, fixed it. But I cannt figure out the surging problem. I've replaced the gas line and primer bulb from tank to motor. I've replaced the set and needle valve in the vapor bowl. I've rebuilt the fuel side of the vro2 pump. Rebuilt the carbs and cleaned the throttle bodies. Now I'm not sure where to turn next. Maybe the vapor pump? The pickup line and anti-siphon valve? And what exactly are those little tubes in the carbs when you open the bowl, are they some kind of pickup? Not sure if I cleaned them good enough?