I am using an os#8 plug, it has 1.5 gallons on it and its due for a change the very last coil isn't glowing and it ran like crap today but no unusual problems except it died at half a tank and it would not start just sputter. The idle is fine it'll sit there and run long enough to refill my fuel bottle and the tank no problem. No binding today but I only got a half tank run. I'am thinking about getting new shoes will the aluminum ones grip the bell better?