Try new fuel.

If maybe your friend has lots of the old stuff and doesn't want to just throw it out, here's something I found somewhere
sometime about water contamination:
"Try digging up an hydrometer, maybe at a brewing supply store.  Pure methanol has a specific gravity of .7913.  It goes up when water gets in it, so any change in the reading is likely enough to cause problems.  Each .0001 change is about 1/10 of 1%."

You can borrow mine if you want to come get it. 


Terry

The real solution, IMO, is improved "fuel handling" techniques. Any system that keeps the jug as air tight and waterproof as possible is what you want to work toward. Opinions vary on how best to do that, but Brett says to fill the fuel tank and suck out excess fuel to get to the correct fuel load for your plane/engine for that day.

Brett doesn't like the "mayonnaise pump", but I do. Each stroke of mine (after priming the pump) gives exactly 1 oz. If I need 5.75 oz in my clunk tank, I pump in 6 oz  and pull out 7cc's with a 1 oz syringe, and squirt it back into the jug. The difference here is that the clunk tank does not work with "cutoff loops", so it's always quite consistently emptied, unlike a typical metal tank. Relative to the subject at hand (water in the fuel), very little time is spent with the fuel opened to the atmosphere.

Also, fuel filtering is only done in one direction...many guys will suck fuel into a syringe through a filter and then blow it back into the tank through that same filter, but the other direction. Easy to see that what crap was initially caught in the filter is then pumped into the fuel tank. That's not good!  Steve