Briz, I am not sure of the specific gravity of the fuel you are using. In some cases the floats need to be dropped if the fuel is significantly lighter or there is a need to overcome pressure at the float valve.
One thing to try is to tap a clear hose into the bottom of the float bowl and to run it up alongside the carb. The fuel level in the hose is the same as it is in the float bowl. Try it with gasoline in the carb first to see where it should be. Then, try it with the fuel and adjust the floats till they give the same height when the bike is running. Remember, the deeper the float is pushed down into the fuel the more pressure it puts on the needle.