Originally Posted by
acdii
SO, when you want a half tank, do you uncap both, and fill the 16 one until fuel comes out 32, and if you want a full, just uncap 32 until it comes out the exhaust?
If you want 16 oz uncap the 16 oz line only. It is exiting from the tank at a lower point so gravity will overflow the line long before the vent line is reached.
If you want 32 oz uncap the 32 oz line only. While the muffler line won't overflow when filling to 16 oz, it will when filling to the full 32 oz. The 32 oz overflow is merely "T"ed into the muffler (vent) line.
The muffler line is convenient to get to so it can be clamped W/hemostats. I want to recover excess fuel W/O contamination W/burned lube in the muffler & return it to be used. If recovery isn't desired, the overflow will run out of the muffler when the tank is filled to the full 32 oz capacity if nothing is done.
The following is how it was plumbed before I got the better fuel dots & located them in the side of the fuselage.
Originally Posted by
SrTelemaster150
Now we address the fuel tank & plumbing the duel level overflow lines.
I uses 3 tank lines. The 2 on the top are the standard clunk & vent lines but the one in the center bottom is an overflow line that barely goes into the tank just beyond the stopper. Its purpose is to allow 1/2 of the 32oz tank to be filled to a consistent 16oz.
The vent line is "T"ed & the 2 lines exit the hatch under the chin.
The rear line overflows at just a smidge over 16oz, the front line is the full 32oz overflow through the vent.