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danielabernath

Well Known Member
I went up in RV 12 that has been sitting in Florida for a few months (Its a long story).
Removed 2 l/2 tubes of water from sump and then tried to fly.
But she sputtered so we aborted the flight. (me and CFI Rhonda Colburn-a wonderful person and CFI).
So I did another drain underneath at the sump.
We went up with nose up and she balked. Would not get to more than 4400.
I and she heard a 'bang'.
I gave her the plane and she got us back on the ground.
We noticed that when nose is down she shoots to 5500. We did 5500 on final.
When nose pushed up, then sputters and gets down into the 4400's.
Once on the ground I did another fuel check and found nasty brown stuff (NOT much) on the bottom of the tube.
I have 2 a and p men working on it Saturday.
What do you think?
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Picture of W.S. in N262WS
 
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I guess I'd suspect water in the tank. If it were me, I'd hold the tail down, turn on the electric pump and drain out of the gascolator until empty.
 
By holding the tail down, the water would all run to the rear of the tank and hide there. Not sure why you would want to do that. Seems like lifting UP on the tail would be better for getting the water out.
 
Stale gas

Maybe it's not just water. Gas gets pretty funky when it sits too long. 3 months is usually not long enough, but you shouldn't get brown stuff. Stale gas stinks too. Easy to identlfy.
Sound like a carb cleaning is due as well.
 
You didn't say what kind of fuel. Auto or aviation. Aviation fuel holds up quite well for several months and even years. Auto fuel, not so much.

I would suggest draining the entire system and flushing out lines, then refill with fresh, or at the very least, filtered fuel.
 
DonFromTX said:
By holding the tail down, the water would all run to the rear of the tank and hide there. Not sure why you would want to do that. Seems like lifting UP on the tail would be better for getting the water out.
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Ooops, yeah my mistake. I was thinking the outlet was at the rear but, you're right, I had it backwards.
 
danielabernath said:
It is auto fuel. Smells like auto fuel when in tube (and spills on my arm)
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In that case, I would drain and flush the system, filter the fuel and put it in my car mixing a little at a time with fresh fuel.

Put fresh fuel fuel in the aircraft.
 
Auto fuel most likely has some alcohol in it--------and water and alcohol mix rather well.

I second Mel's advice----------drain, flush, and refill.
 
100ll goes to heck also. I had my Ercoupe sitting in a closed very hot hangar for several months, and it would just barely run after sitting that long. I mixed a lot of fresh 100ll with it and it decided to fly at least, still not too happy.
 
You should also check to see if your RV-12 is affected by the carb float issue. As someone else suggested may be a good idea to clean carbs - would be a good opportunity to check the floats.

TB
 
It also might be a good idea to become familiar with some of the documentation related to owning and operating a Rotax 912 and an RV-12.

For this particular situation, THIS document might be a good place to start....
 
"It also might be a good idea to become familiar with some of the documentation related to owning and operating a Rotax 912 and an RV-12.:
Mo Gas is corn-free
NEW FUEL OPTION NOW OFFERED AT PAGE FIELD
FORT MYERS, Fla. (June 30, 2010) – A new 24-hour self-serve mogas (motor gasoline) fuel station is up
and running at Page Field General Aviation Airport (FMY). The 1,500-gallon tank dispenses 93
octane/ethanol free unleaded gas that fuels many light sport planes as well as aircraft with a Supplemental
Type Certificate (STC) that run on unleaded gasoline. The addition of this fuel supports the ongoing
development of Page Field and the services it can provide to its general aviation customers.
For this particular situation, THIS document might be a good place to start....[/QUOTE]
I fueled up from the Ft Myers Page Field fuel tank for car motor gas a week ago. Probably down to 5 gallons of old motor car gas from months ago. I'll ask Base Operations if they put ethenol into motor car gas. Willy Nelson made em do it for the farmers, eh? Burn what we can eat. Makes sense, right?
 
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And.........I shake and rock the wings to get the condensation off the tops of the tanks and allow time for the water drops to migrate to the sump.
 
bret said:
And.........I shake and rock the wings to get the condensation off the tops of the tanks and allow time for the water drops to migrate to the sump.
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I talked to someone at FAA and he said that the old pilots with the old planes used to do this every morning.
Thanks for the tip. I'll do that as part of my pre flight inspection.
 
danielabernath said:
I talked to someone at FAA and he said that the old pilots with the old planes used to do this every morning.
Thanks for the tip. I'll do that as part of my pre flight inspection.
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It is not likely to make any difference on an RV-12, because it has an entirely different fuel tank design than a lot of other aircraft..... not much of anywhere for water become trapped.

If it were my airplane, I would be trying to figure out how the water got in there in the first place... the way the fuel cap is positioned, it is not very likely for water to be able to sit within the recess of the cap and leak past the cap seal.
 
I was thinking about tapping on top of the fuel tank to get the water to leave its clinging to the roof of the gas tank. Might be a futile act, however.
 
Mel said:
In that case, I would drain and flush the system, filter the fuel and put it in my car mixing a little at a time with fresh fuel.

Put fresh fuel fuel in the aircraft.
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Mike S said:
Auto fuel most likely has some alcohol in it--------and water and alcohol mix rather well.

I second Mel's advice----------drain, flush, and refill.
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+2 - Absolutely! And you might need to replace the fuel filter too.

I got "bad gas" in my Volvo once (it only had 5k miles SN at the time). It was immediately running poorly. I pulled out the sending unit/pump from the top of the tank and looked in with a flashlight - there were two fluids there - a clear layer on the upper half and muddy brown layer on the lower half. Drained the tank! Horrible smelling stuff on the lower half. Straight from the pump.
 
Bad gas

BillL said:
+2 - Absolutely! And you might need to replace the fuel filter too.

I got "bad gas" in my Volvo once (it only had 5k miles SN at the time). It was immediately running poorly. I pulled out the sending unit/pump from the top of the tank and looked in with a flashlight - there were two fluids there - a clear layer on the upper half and muddy brown layer on the lower half. Drained the tank! Horrible smelling stuff on the lower half. Straight from the pump.
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Bad gas stinks almost as much as differential oil. Yuk. I use Stabl in any gas sitting more than a month. Not sure how it would work in Avgas though.
 
Page Field Mogas

The MOGAS at Page Field is alcohol-free. Unfortunately, it is also considerably more expensive than the 100LL. When I was there in February I filled up a Tecnam twin several times. I cringed every time I looked at the price, and wished I had my 100LL-burning RV4 with me so I could take advantage of the excellent avgas price.

Old gas is filthy stuff. You've got good advice to get rid of all of it. If you suspect that alcohol has been sitting in it for a long time, remove a fuel line near a carburetor and look for evidence of internal failure due to chemical contamination. I've seen it many times in car-gas fueled 912s with results ranging from rubbery-sludge on the fuel inlet nipples, to dramatic corrosion of the carburetor internals.

Good luck, and please report back with your progress!

Wayne
 
I met this Saturday morning with two pilots who like to A and P on the side.
They agree with you all
a. drain the entire fuel system
b. install new fuel filter
c. check the float (even thought this Rotex 912 engine is NOT on the list but you never know)
d. use gasoline from Wawa gas station (just expanded to SW Florida). They said that it is $3, not $5 and is non-ethenol and 93 octane).
e. we discussed my theory that perhaps as KFMY gasoline is so expensive that anyone who wants to us "mo-gas" would refuse to buy it at the fuel farm and gets it from a gas station THUS causing that fuel to be bad as it just sits there and sits there. (there is a sign up at the mo gas tank that I use it at "your own risk." WTF could that mean?)

Dan
ps, they say they can get to this in a couple of days
PSS, what is the fuel filter number for the RV 12? It is a fuel filter for the Rotax 912 that I'm looking for?
 
The RV-12 (if built per plans) does not have a fuel filter that requires replacing. It uses a traditional gascolator that contains a very fine filter that can be removed, washed and reinstalled.
As I suggested previously.... it would be a good idea for you to get copies of all of the documentation (including the Maintenance Manual). With this you would have a lot of the information you need to maintain and operate your RV-12
 
I'll dig it out having moved from Oregon to Florida. Found the log for assembly and it already solved a mystery so I shall keep digging.
Thanks for the guidance.
 
Dan, Let us know when it is running smoothly again, just to hear a happy ending.
 
The rotax dealers around here give maintenance courses. These are rather complex enhines comparedthe lyc flat 4s. I would encourage you to find a dealer who offers something near you.
 
Good advice from Scott. You're not far from Sebring. Lockwood Aviation there knows the Rotax well and I think they may have some classes. Of course you'll need to make sure you can safely get there.
 
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I also think I should top off to the top of the neck after each flight. That way there can be no condensation there or inside the gas tank--thus no water.
 
danielabernath said:
I also think I should top off to the top of the neck after each flight. That way there can be no condensation there or inside the gas tank--thus no water.
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The tank needs some air space for fuel to expand and retract with temperature changes. As long as the tanks are close to full, there is not much air to provide moisture that will condensate.

I agree with others that you likely have some bad fuel in the tanks. Always test MOGAS for ethanol before use. It is easy and takes only a few minutes. Add a small amount of water to a tube or small container that can be sealed. Mark the water level. Add fuel to test. Shake until well mixed (30 seconds). Wait for water to settle. If water level appears to rise, you have ethanol that is binding to the water. If the water level goes back to the line, all is well; go fly!
 
While not a 912, I was surprised by the amount of gunk and water in one of my two Honda 2000 watt generators. Before packing the travel trailer for OSH this year I tried to start both. One started and one didn't. They were both started in the spring but were not drained.

The amount of gunk and corrosion in the fuel bowl really surprised me! That surprise was only superseded by the amount of water in the fuel tank.

It convinced me to NEVER run tainted fuel in my plane and if I had a 912, I would test every batch of auto fuel or MOGAS before putting it in my tank to make sure there is no ethanol in it!
 
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