Fuel mods continued...

[MarkT]

I think I'm pretty much done with my experiments with the belly tank.  I replaced the OEM barbed T-fittting between the fuel rails, with a brass one that I could screw directly to the Dan-Marc.  That saved me almost 2 inches.



Which allowed me to leave the fuel filter in place upstream of  the Dan Marc and still connect to the petcock while keeping the flow all downhill, no loops.





Moved the belly tank fuel pump line to the Bung-filler line, above the solenoid, with a couple brass T's.  Also added a fuel drain / rescue petcock on the end of the smaller T.  The 1/2" copper line will be shortened when I determine the length it needs to be, before flaring the end to fit the bung flare fitting.  I'll button this up tomorrow.  Wish I could take it for some test rides but the snow just won't melt.

[MarkT]

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?

[John Schmidt]

Mark, I looked for a tee such as the one you used to screw into the DanMarc, found everything but the size needed to go into the solenoid. That was some time ago so might look again. I'll probably not go into making a change re. that tee until next time I pull the airbox. As for lube to use on metal to rubber such as pressing hoses onto barbed fittings, I just use ordinary rubbing alcohol in a small spray bottle.

Project looks good, hope it works OK.