I just got back from another serendipitous (sp?) day of flying weather here in the frozen North.  Sunshine, high 50s temp, light breezes.  Great.

Took out my SkyWriter, the newly-designed Rumbler, and the Hexdrone thing I got from Frank.

SkyWriter continues to impress--I may not ever try it with an .061 since it flies so well with the .049. 

Rumbler, fast and quick-turning, best I could tell on the truncated flights (more on that in a minute).

Hexdrone--Frank, you should have tried to stunt this thing...what a ride!  It is fast, I'm thinking of pulling the .061 off and putting on an .049--at least the tank would be big enough.  Pretty squirrelly manuevering, kinda like the old Half-Fast or Wow flying wings combat planes. Not particularly stable, very touchy and jumpy and "twitchy".  Kinda fun though.  It might be tamer at a slower speed. I have better places for the .061 than on this.

The truncated flights:  None of my engines needled well or consistently today.  I'm not sure I ever ran a tank out...either starved out lean or flooded out rich.  And the difference many times was just a click or two.  I'm used to tinkering with 1/2As, but these needled very hypercritical even for me.  I even changed to different kind of tanks on two of them. No help. 

I'm thinking it's time to buy some fresh fuel...what I have is maybe 2 years old, only about 2" left in the bottom of the jug.  It was only 15% to start with, maybe it's dropped below some critical level for these little engines? 

Anyhow, I'm planning to try some filters in all the lines next time out. 

Any suggestions accepted and considered.

--Ray

I've never had a problem with old fuel in a can or jug, and I've stored it for ten years or more.

I would guess the that the issue might be old fuel in the engine or fuel tank.  When it dries up and gets funky, bad things happen.

Another issue might be cold weather performance of otherwise good fuel.  On the few occassions where I've felt the need to test something in the cold, the fuel has not been good to me.

If you suspect your fuel is questionable, don't hesitate to try fresh fuel.  If the new fuel solves the problem don't contaminate it with the old fuel just to save a penny. 

BTW Ray I'm fireing up the .010 in a little while

Plastic bottles are porous to things like other chemicals and moisture, fuel stored in them will eventually evaporate and also absorb water from the atmosphere through even a sealed container.  Get some metal cans.

Before you completely give up on the fuel, consider that the cooler weather brings denser air---more O₂ to burn. Just like adding nitro. Not bad, but in this case you may be effectively over-compressed. With high nitro fuels I typically will add a head shim. Just a thought.