S.U Carburetter Float Needle Valves
N.W.Geeson

Anyone who is overhauling the S.U carbs would be advised to use spring loaded float chamber valves, which are S.U part number WZX1101. They are available from Burlen Systems.
These float needles are not shown in the recommended list for our cars simply because the needles did not enter production until the early 1960’s, when they were produced for the Monte Carlo rally Mini’s.
The spring-loaded arrangement allows the needle to exert a constant pressure on the seating and it is therefore not so susceptible to flooding.
It should also be pointed out that the constant depression S.U carb is NOT dependant upon exact fuel level heights but fuel should be visible down the jet orifice when the dashpots are removed. However it is important that the fuel level is not too high, which does occur when the float levers are set to workshop manual settings. Modern fuels demand that the levers are set lower, and any amount of flooding by having fuel level high in the jet, is to be avoided.
Float needle valve bodies cannot be changed on S.U carbs without distorting the valve body unless the correct extra slim S.U box spanner is used. This special but cheap spanner is available from Burlen.