fuel contamination

[voitty]

I am just after some different opinions as to what effect water contaminated fuel will have on a 2 stroke engine mine being an OS 55AX .this engine starts fine idles fine but always dies after around 2 minutes of flying I have done all I can do trying everything and am wondering if water in the fuel can cause the 2 stroke engine to run lean any ideas or similar problems would be good to here as my saito 100 had a similar problem and with new fuel is like new.

[3D1]

the only time I have had a problem like that I had the fuel and vent lines hooked up wrong

[RCAddiction]

Usually, for me, contaminated glow fuel will cause the engine to run poorly from the moment it accelerates takes off. Yeah, it will idle fine.

Mix the fuel
You didn't state which percent nitro you are running (10%, 15%, etc) but Wildcat once told me it was good practice to gently shake the gallon container of fuel before each day's flying, to ensure the nitro, etc remains properly mixed. Apparently, the higher percent nitro fuel (20% and up) tend to be more sensitive to the nitro not remaining in solution.

Fuel lne
You might have something as simple as a pinhole leak in your pickup line, causing the engine to suck air once the fuel level drops a bit. Or, you might even be accidently have the vent and fuel pickup lines swapped.

Lean/Overheating
Is the engine head very hot when it dies after you land? Doublecheck that the engines are not too lean, and are getting adequate cooling (cowl venting) and not simply overheating and quitting.

Step 1
Make sure the fuel lines aren't swapped (vent/fuel supply). Check for lean/cooling issues. If ok, then try a new, different container of fuel. Shake it to mix it and fly. If the problem goes away, you probably did have a problem with that fuel. If you still have the same issue, start replacing fuel lines, look for tank leaks, etc that could cause air to be sucked in.

[bgold]

Get some new fuel, if the problem persists then you have other issues.