OK, not my favorite carb, but maybe this will help.
The vacuum piston is designed to be operated by negative pressure (vacuum). Virtually all pistons will have some binding if pressed on rather than being pulled. Try applying vacuum at the vacuum source.
The float will not need a different adjustment with E-10, but the fuel jets (both idle and main metering) may. We suggest opening the idle jet 0.002 inch, and the main metering jet 0.001 inch.
Once the idle jet is enlarged, the idle mixture control screw may function as designed.
Contrary to popular opinion, the idle mixture control screw does NOT control the idle mixture! Rather, it controls the volume of the preset idle mixture which is determined by the values of the idle jet, the idle air bleed, and the idle bypass. For an analogy, think of a three faucet shower. The hot water would represent fuel; the cold water would represent air; and the big knob in the center that controls the amount of water represents the idle mixture control screw. In the case of the carburetor, BOTH THE FUEL AND AIR INPUTS ARE FIXED INSIDE THE CARBURETOR UNLESS MODIFIED. Opening the idle jet as suggested above does make the mixture richer.
Jon.
