Compatibility KEIHIN MAIN JET #99101-357SIZES: 175 180 185 190OVERALL LENGTH = 16.5mmDIAMETER = 6mm� Keihin FCR racing carburetors� Keihin FCR single carburetors� Keihin FCR MX carburetors� Keihin CR special carburetors� Keihin PE / PJ / PWK / PWM carburetorsKEIHIN PILOT JET #424-21-52 # 424-21-58SIZE: 52 58OVERALL LENGTH = 28mmDIAMETER = 5mm� all Keihin FCR MX carburetors� all Keihin PWK / PWM / PJ / PE carburetors� some Keihin CVK carburetors.