You don’t have to believe it but that is what happened. I even put the 6 plugs in a different engine different glow igniter with the same result. I put an O.S plug in as suggested from another novarossi racer and have not had one problem after the switch. I could have sent them back but I already put an O.S plug in the engine so getting new nova plugs would not do me any good. I would not call this “bad advice” if it’s my experience. No one reading this has to use an O.S plug in their novarossi just because I am. Both of my engines run great with a P3 and my fuel mileage is just as good as anyone
else racing with me. Again this is my experience only so do what you want. I will continue to use O.S plugs in every one of my novarossi engines.