sandpaper? lol....just get a new plug before you get screwed again with that fouled one.. a new plug is 1.50 at the auto parts....premix doesnt make a 4 stroke run that bad, as long as you dont have the crappy oil mixed in.....if you need to use some make sure it is a castor/synthetic mix....dont use petro based or you will foul plugs and you might as well not even ride it...
1985 Honda ATC250R drag trike with s/t kit and full drag CR hybrid motor and drag chassis...
1986 Honda ATC250R daily rider fully modded engine, +4 swinger,etc...
1997 Polaris Storm 800 triple, boyesen reeds, dg individual silencers, 240 studs, 123mph on radar...