Main Jet Mikuni #250 Hexagonal Type True to size, as Mikuni jets are drilled and not stamped – each jet is reviewed on the correct flow rate ! Main jet, type B, hexagon head, A/F6mm, thread M5.3×0.9mm Fits Mikuni serial carburetor with Round slide (VM type; SR500 ages up to `89 and all XT500) In increments of 10, from # 220 to # 330