What's the nuclear option for a leaking needle valve

I have written a few posts on my Hoinda GVC 160A problems. The carb needle valve will not shut the fuel off from the bowl . Last fall after many years of service the carb was leaking and the parts were equal to a new carb. I get gas flowing out the main jet of the carb. I first replaced the carb with a brand new OEM Honda. Then I ordered the suggested float that has a means to adjust the float level. I lowered the float level slightly hoping that would apply a little more pressure on the needle valve to seal closed.
With all this I still have a needle valve that will not seal the gas flow into the carb bowl.
Does anyone know of a solution? Is there a needle valve with a larger rubber tip or longer? Has anyone polished the carb body where the needle valve seats? Could the tank be pressurizing to cause the float not to seat?
I have a ME degree and worked on cars all my life but............
I am about ready to push this thing in a fire.

What's the nuclear option for a leaking needle valve