hi there i have got a 2005 king quad 300cc when i get it started it backfires and sputters then cuts out when i take out the plug its full of fuel once cleaned it will start and run for a short time.

brian, January 2010

i would say either the float needle is sticking or the float needle seat is worn or the float has a hole in it or possible the needle seat has an oring on it that has gone hard and its leaking past outside of the needle seat.does the plug smell of petrol or is it just black as it could be burning alot of oil and fouling the plug up not that likely but possible.

adam bike doctor, January 2010