I have had a fuel leak from my left carburetor for about two years now. I have replaced the float and needle and it still leaks through to the overflow hose. At this point I have it going to a small external reservoir which I dump back into the tank. If I don’t do this I will loose about 1 gallon for each tank I run. I have heard from other sites that this is a failed internal seal that cannot be replaced. I thought I would throw it out here and see if anyone has any ideas…