A kit for the 6 and 9 series carburettors comprising of a matched needle jet, throttle needle, and jet holder. This can be used to replace worn parts, or to convert a 2 stroke carb for a 4 stroke application. It can also be used where you have an early 4 stroke carb with the needle jet which is not cross drilled. In this case you need to replace the needle jet, jet holder and throttle needle as a set. This kit had original part number 622/235. All the components are also available individually.