Amal Concentric on 1950 NH

[david.anderson]

Peter
I run 32mm concentrics on my VHs without any float height setting problems. In fact concentric carbs my be inclined at up to 30 degrees and still operate correctly. So unless you have an incorrectly machined concentric, you should not have any problems. when the top of the float is set at .040" below the top of the float bowl, the fuel level will be .24" below the top of the bowl.
David

[PeterW]

Peter
I run 32mm concentrics on my VHs without any float height setting problems. In fact concentric carbs my be inclined at up to 30 degrees and still operate correctly. So unless you have an incorrectly machined concentric, you should not have any problems. when the top of the float is set at .040" below the top of the float bowl, the fuel level will be .24" below the top of the bowl.
David

Thanks David. That's interesting - I have thought that the problem with mine is that the float is too buoyant and therefore sitting too high in the fuel. Is yours a black plastic float?

[Brian_Walker]

Peter the height of the float is controlled by the position of the float needle and seat not by its buoyancy, if float is too high and carby is flooding then the float vale needs to be lower to shut off the flow of fuel at a lower level. If too low the valve is raised so more fuel can enter the bowl before fuel flow is stopped.
Hope that explains it more clearly.

[david.anderson]

Peter
My concentrics have the white floats, ie older type not suitable for ethanol. With the black stay up floats you can bend the stainless tang to adjust the fuel level.
If you have a brass viton tipped needle throw it away as it is too heavy and results in a lower fuel level. The aluminium viton tipped needles are ok. The best way to check fuel level is to fit a dual fuel banjo to the float bowl. Attach one side of the banjo to the fuel supply and on the other side attach a clear plastic tube and put a bend in the tube and run it up alongside the carb body. When you open the petrol tap the float bowl will fill and you can see the exact fuel level in the clear tube
David