I made my own 1.75 gal tank that looks and fits similar to the X-tank that's plumbed off the top of the factory's vent, same as everyone else's is plumbed and have only had one fuel flow or transfer issue in 16K miles. My only issue was due to the rubber gasket between the factory gas tank and the locking gas cap started to leak a little. I first noticed a little fuel leakage on the side of the tank after the bike was topped off. Then one one occasion the low fuel light came on at around 100 miles and no fuel was pulled from the accessory tank. That gasket leak at my main tank filler "broke" the vacuum that pulled fuel from my accessory tank as the main fuel was used. A quick tightening of the bolts that hold the filler in place brought everything back to Golden, and all has been well ever since.