[PaulProe]

John
using the caliper is the same as using the optical gauge. both react when they touch the fuel - the optical gauge changes color - the caliper shows slight movement of the fuel level as the surface tension changes and wraps to the caliper point.

In both cases, the magical number for 48IDA's is 43mm from the floor of the emulsion tube/jet well (the area covered by the screen) to the fuel level.

I've verified this number by using fuel to float the float to the 5.75mm level then replacing the cover & gasket and measuring. I did the test repeatedly to confirm the results. I then also did measurements using an AutoCAD layout and it verified this dimension also. Dean Lampe (who used to be active on this forum with his Webers) learned of this also from an old time Weber mechanic.

I also used the caliper method however it is difficult to find a caliper that has a small slide extension. The cheaper ones are almost the same width as the tube well and very difficult to use.

I've sent you a PM also

Paul