I have a 1978 Evinrude 6 hp motor which has been very dependable. Last year I rebuilt the carb and fuel pump, installed new spark plugs, impeller, etc. I have been using it several times every week. It is now starting pretty much like it always does, but now it will surge, then fade out, then surge, then fade out, etc. until it stalls. I am thinking the float or needle, (or both) are getting hung up. Does that make sense? Please advise. Thanks.