Whatever the cause of the current hard start problem, I use a starter for the simple reason that I agreed with my wife to do so after I almost lost a finger to a flipped engine. No, I don't want advice on how to flip safely, thank you. The fact that the engine does run perfectly after warm up indicates to me that, since the carb is lugged down very tightly and has been sealed with gasket sealant on all gaskets it must be a mixture problem not an ignition or fuel supply issue. Next weekend I shall try the richer mixture scenario first.