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RV12 Fuel Draining

N621DF

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Any recommendations?

I have been due for a Biennial Flight Review during a prolonged Covid19 lockdown and an Annual Condition Inspection, so I haven't flown my plane in several months. I would like to drain the months-old fuel in my RV12 and replace it with fresh fuel. It seems that the safest and most efficient way would be to connect a tube to the bottom of the Gascolator valve and pump the old fuel out with the electric fuel pump. Has anyone done this or have any recommendations?
 
Any recommendations?

I have been due for a Biennial Flight Review during a prolonged Covid19 lockdown and an Annual Condition Inspection, so I haven't flown my plane in several months. I would like to drain the months-old fuel in my RV12 and replace it with fresh fuel. It seems that the safest and most efficient way would be to connect a tube to the bottom of the Gascolator valve and pump the old fuel out with the electric fuel pump. Has anyone done this or have any recommendations?

Yes, I have done this many times.

  • Shut off manual fuel valve
  • Replace drain valve in bottom of gascolator with long pipe nipple
  • Open manual fuel valve
  • Run electric pump
Tank will empty completely...
 
Yes, I have done this many times.

  • Shut off manual fuel valve
  • Replace drain valve in bottom of gascolator with long pipe nipple
  • Open manual fuel valve
  • Run electric pump
Tank will empty completely...
Would there be any point in draining the carb bowls to get rid of the fuel that's already past the gascolator?
 
I just emptied mine yesterday during condition inspection and did it pretty much like Jim listed above. However I removed the fuel line from the top of the gascolator and attached a two foot hose into a fuel can. Using the electric pump to get the gas out but be aware as you near the end the tank baffles slow the flow. I shut things down for a few minutes and allow the gas to drain forward. Then start again until the pump starts to clatter, stop and let the fuel move forward, then again till clattering again.
The last part takes three to four times to get all the gas out.

I would remove the float bowls to get that gas out too.
 
I wouldn't drain float bowls unless fuel was really old. When engine starts the fuel in the bowls will get consumed quickly at low engine power. Even if octane is way low it won't hurt anything for short time period.

My fuel sits in the tank from Nov - April because grass strip is unusable until ground dries up in the spring. I have original vented fuel cap and not the new style filler tube vent. With small hole in the vented cap there is very little air exchange in the tank. Tank remains half full in the winter and I add fresh 93E10 to top of tank before flying season starts.


This is why I'm not flying now...
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My grass strip could look the the same during the winter months ,but I keep my grass runway clear with my 3020 John deere and 7ft snow blower . I fly year round . I have 15.5 hours in December and 9 hours in January . I fly year round. Winter flying is actually better.

Not bad for South Dakota.

Brad Stiefvater
Salem SD
124 BJ
 
The RV-12ULS Maintenance Manual (starting on page 13-4) documents (step by step) the recommended procedure for draining the fuel tank.
 
If your engine runs with normal indications why not just use the fuel as opposed to assuming it is bad? If you don’t have a full tank just add fresh AVGAS if it gives you more confidence.
 
Ever since I've had my RV12 about 2.5 years now I've added 1 oz. of "Sea Foam" to each gallon of gas, it claims to stabilize gas for 2 years. This product has been around since the 40's...it helps to reduce carbon build up, keeps carb jets clean and is an upper cylinder lubricant. I've been using it for about 170 hours, engine runs smooth and it quick to start. I've heard of others using "Stabill" but since I use Seafoam in my boat so I've chosen to use it in my RV12 as well.
 
fuel tank draining

I routinely use a process similar to that described by PiperJ3. I temporarily replace the gascolator drain valve with a brass pipe nipple that has a 1/4-inch tube fitting on the other end and slide on a piece of flex tubing about a foot long, which reaches neatly into my 5-gal fuel jugs sitting on the floor. Running the electric fuel pump to drain the tank does not run the battery down enough to cause any trouble.

Taking the fitting out of the bottom of the tank always seems to get my arm soaked with fuel clear up to my armpit, so I avoid that whenever possible.
 
draining carb float bowl

BTW, I had serious trouble from leaving 93E10 fuel in my float bowls for about ten weeks while I was completing my build. The little transverse holes in the idle jet on my left carb plugged up with dark goo and the engine would barely run. Fortunately Lockwood Aviation was able to coach me by email and taking out the idle jet and cleaning it was all it took to fix the problem. But I will never again leave fuel in my float bowls for longer than a month or so.

Now if I think the plane may sit for a while, I close the fuel valve in the cockpit with the engine idling and let it run until it quits from fuel starvation. That should almost empty the float bowls. This process was recommend for winter storage of my lawn tractor and it seems to work.
 
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