I am not familair with that plug, but I can tell you that I had put a different four stroke plug in one of my YS engines and it gave me fits until I put a YS or OS #F plug back in it. The YS and OS plugs are supposedly the exact same plug and they are what you want.

If you are getting fuel to the carb the rest of it's journey is not easily blocked. It goes down to the crankcase and then up into the airbox and into the cylinder once the valve opens. New engines are good for contaminating plugs with microscopic bits of metal as the parts wear in. Change the plug and let us know if it help or if there is no change.