The measurements are made (wihout a gasket) with the air horn upside down on your bench. With the float hanging by its own weight the clearance between the float top and the air horn should be 9.8mm (raised position). Lift the float and the gap should be 48mm (lowered position). There are tabs on the float to bend for these adjustments. There should be a sight window on the side of the float bowl. The final adjustment is made on the engine with the adjusting screw to put the fuel level in the middle of the window. These numbers come from the '85 shop manual, but worked fine when I overhauled my daughter's '87.