n7tb

I have a metal 1 gallon fuel can. I used to pour the whole one gallon castor-based fuel from the plastic jug into the metal can. I found that after several months of the fuel sitting in the can, especially after the fuel can was 2/3 empty, I would start having my 2 Cycle engines start to behave irratically. They might fly fine the first flight, then after a refueling with the engine warm, I would start the climb out on takeoff and the engine would quit. I dinged up several planes this way. After tweaking with the mixture, etc. I had a fellow tell me that I probably had moisture in my fuel.

I would then buy new fuel and the plane would fly perfectly. It leads me to believe that he was right but I am not sure. I now buy fuel then pour it into full quart bottles to keep it from getting air into it, then use the fuel 1/4 gallon at a time. In the summer when I fly more, it is not much of an issue, but in the winter, I don't get to fly much, so I use this method. Am I crazy or is moisture in fuel a problem that others have had? I know that the alcohol can absorb water, but I keep the container closed. The only water would come from the air that exists in the fuel can that might get more moisture when opened and used.

I would be interested to hear what others have experienced with moisture in fuel. Sometimes I question the advice the fellow gave me, but every time I start to have trouble with engines not running well, it is usually after using fuel that has sat in a half full container for a few months, and new fuel always makes my engines fly great.

What do you guys think?

Thanks,

Terry

Sport_Pilot

If you have well sealed cans you shouldn't have a problem with moisture no matter how little fuel is left in the can. Another problem could be corroded brass fitting which can cause some of the fuel to decompose. The same thing can be happening to your airplane fuel tanks, any remaining fuel pumped into the jug would then be contaminated.

I don't know this for a fact, but was mentioned in a recent Model Aviation article.

JoeAirPort

My Feedback: (41)

Yeah this guy in Model Aviation put 20% water in his airplane's tank. He richened up the needle valve a half turn and the thing ran perfectly. It's not the moisture. It's something else.

Joe

RaceCity

Bull.

Keep your fuel sealed...keep the water out of it or you WILL have trouble.

The MA test was garbage. Try getting a reliable idle...transition, etc with waterlogged
fuel. I suspect the results would have been far different had he not used a c/l motor
fixed to full power.

My $0.02

'Race

Sport_Pilot

I have to wonder about the test myself. Not sure you can mix in that much water without some oil seperating out. However I do know that small amounts of moisture will run OK if you go to a hotter glow plug. But that may not help much if you have a habit of using the hottest glow plug out there.

RaceCity

SportPilot...

I think an actual analysis of fuel, using the chemical makeup of a control sample and that same
fuel once it has been exposed to UV, oxygen, moisture, lead, brass, nickel and whatever else the fuel
comes into contact with over time in an actual modeling environment would be informative.

What components of the fuel disappear...decompose...or otherwise change in some way so as
to cause a motor to simply not want to run?

The MA test was less of an actual "test", and more of a "stunt" IMO. I don't see much scientific
merit to it at all the way it stands.

'Race

downunder

I've mentioned it here before but these things can get missed. Just for curiosity I did some tests starting with fresh fuel and gradually adding water to see what would happen. At 3% water the engine still ran exactly as it did with the fresh fuel and I flew it as well. None of this wimpy test stand stuff But at 4% water all the oil suddenly settled to the bottom of the tank. Now with the clunk at the bottom of the tank the engine found it hard to even pop with 100% oil going through the carb

This is why I simply can't believe that 20% water article, CL engine or not.

RaceCity

Maybe it was because you're in the southern hemisphere? <GGGG>

Coriolis effect...all that stuff comes into play....<grin>

(Can you tell I've been up waaaay too long?)

It's just ridiculous. All the pains the manufacturers take to prevent moisture entering
their product during manufacture, and then some goof article comes along and attempts
to disprove it all. Bahhhhhhhh.....

Let him dispell all the "myths" he wants. I prefer dry fuel.

'Race

Sport_Pilot

I do think it a myth, I used to add water to alcohol fuel in my drag racing days to avoid detonation. I have had fuel I left open for weeks, still ran good just had to use an Enya #3 plug and opened the needle a click or two, no oil seperation.

Even so I wouldn't want to buy fuel with water in it. The fact that I had to open the needle is indicative of the fact that the water didn't burn so fuel consumption will go up. At some point its got to stop burning, if not 20% maybe 50%, certainly before 100%.

[sm=bananahead.gif] Unless you use that pill you put in the tank and fill it up with water.

RaceCity

What was that stuff they used to sell in a certain "Automotive catalog"...

"Mechanic in a Tablet!!!".....

"Rebuild your motor WHILE-U-DRIVE..."

"Restore lost Power and Pep!"

<GGGGG>

Where is that stuff when the world really needs it?

Pjtg0707

ROTFLMAO.

Now, THAT'S FUNNY.

RaceCity

Tell us more oh wise one.....do you know differently?

Care to reveal the truth, and show us the way

'Race