Couldn't get the fuel fitting on the bung to stop leaking. Very frustrating. So checked some videos on youtube and learned, you have to use flare fittings on fuels and gases.
https://www.youtube.com/watch?v=3e103_ULgpI Compression fittings are only for water. In fact using them on fuel lines violates code. Turns out vibration can make them leak and cause a fire / explosion hazard. I had used a compression fitting below the flare on the bung fitting. Also note, gasoline is much lower viscosity than water - meaning the molecules are really small; will penetrate holes / cracks water cannot - maybe even more so with ethanol in it. OK, so I replaced the flare-compression segment with a double - ended 1/2" flare union. And oiled the threads and used some dope on the fitting faces (from another video
https://www.youtube.com/watch?v=pvPjOwRnLPY) when they still leaked. All the brass fittings have Permatex #2 (couldn't find #3 aviation dope which is supposed to be better for ethanol fuel) or pipe dope for gasoline on the threads. This compression fitting problem may explain why I periodically have to fix leaks on Deerslayer's air system, which uses 1/8" air lines and quite a few compression fittings. However they are plastic lines and all fittings have teflon tape.
Another note - worth mentioning again. Whenever I need to insert a barb fitting, or into a rubber grommet say on the side covers or the exhaust header covers - pretty much any snug fit with rubber or the like - I use Wire Pulling Lube. Available at Amazon, ebay or Grainger. Consistency of K-Y, a lube that is soap or polymer based, not petroleum, won't hurt rubber. Makes assembly go much easier, saves frustration and forcing stuff when it's slippery it slides right in. But then you knew that right?
