New Throttle shafts which include new O ring seals

I have been rebuilding SU carbs for many years and this modification overcomes a wear problem on these carbs.

After extensive testing I can now offer replacement spindle for the H type carb
 All H2,4,6,8 carbs use an external spring to close the Throttle butterfly, and these springs cause excessive wear on the spindles and bearings as they pull the butterfly shut.Wear in this area causes the mixture to weaken as Air is drawn into the body down stream of the venturi.
The normal fix is to replace the shaft (and bearings) but the new shaft will wear out in exactly the same way because of the external return springs.
In later models the springs were made concentric to the shaft which helps but the shafts still wear because of the torque created by the throttle levers.


This is a modification to the shaft which prevents Air being drawn in, even if the bearing is slightly worn.
'O' Rings are set in precision cut grooves in both bearing surfaces of the shaft, which seal and allow for the slight movements as the shaft turns.

These new shafts are precision ground original equipment supplied by SU Burlen, made from Manganese Bronze.(the originals fitted were brass).

New shafts without the machining or seals cost over £15 each

PLEASE ADVISE CARB TYPE H4, 6 or 8