I bought a Grubee GT5 for my 14 y.o. son for Christmas. I ride a mc & have "mekanekal attitiude" (sp). We built it together but have had trouble keeping it idling. Have read many of the posts @ carbys. Yesterday the fuel mixture screw vibrated loose & flooded the enginesending gas back out the airfilter. I readjusted, bottomed out then backed off 3.5 turns and is still flooding. starts ok but the fuel runs back thru the air filter when running & keeps flowing even after the engine is stopped until the fuel shutoff valve turned. Am getting tired of cleaning the foam each time I trouble shoot. Tthe carb apart: float is free, needle valve free, tickler is not stuck (don't even use it). Any suggestions to make this Christmas present a go that keeps going?