Float Level Adjustment – Series “E”

The position of the forked in the float chamber controls the float height and therefore, the fuel level in the jet. The Workshop Manual for the Series “E” specifies a distance of ⅜” between the fork and a line across the float chamber lid when the needle is seated. This is achieved by using a section of ⅜” diameter bar across the lid.

When purchasing a new needle and seat for the carburetor (the ones in the carburetor bore no resemblance to the originals), I was discussing SU carburetors generally with John Cheal of Wilson Carburetor Service (no relation), who insisted that the correct distance of the float fork was 7/16″ and the Manual was wrong.

So who is correct? I set my float at the 7/16″ level and, with the new needle and seat, am achieving smooth running and good fuel consumption (average of 40.4mpg for the 2400 miles of the Caloundra Rally trip; moveover, inspection of the spark plugs shows that light grey-brown deposit. So, I conclude that the carburation is fine, and, therefore, my vote is for Mr. Cheal.

Jim Wilson