I had the same issue end up replacing fuel filter, ignition cap, rotor and spark plugs. After replacing all these items the problem still persist. After awhile it got difficult to start. I found a post here and recommendation to replace OVP relay. I had a used one in my parts bin that finally fix the problem. I suggest find a use OVP in your local junk yard because this is expensive item to buy for testing unless someone in this forum can show you how to test your old OVP.