MDS .58 Runs Rich

A friend wanted me to post this question concerning his new MDS .58,
"Why does it run rich no matter what the needle settings (high and
idle) are? It runs fine on the bench, but then will load up and flood
out after a short taxi prior to take off. It will sometimes make it
through taxi and take off, but then die in the air. Again from too
rich a mixture.
He wondered if it might be that the MDS needs a longer break-in period
than an O.S. or Saito. He has run about 1/2 gallon through it at
present. After three experienced pilots twiddled the needles, checked
fuel lines, tank, etc, etc.; it still does not run well.
What has been your experience?
Reply to
Tom Johnson
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Fuel foaming. The fuel tank is foaming the fuel due to engine vibration. The model vibrates one way when sitting on the ground. When the model is airborne, it is free to shake in a different way, for lack of a better explanation, and the needle valve adjustment made when the model was on the ground was a "false" setting.
Isolate the fuel tank from the model's structure with soft, unpacked foam and the problem will disappear.
Sometimes just balancing the prop is enough to let you set the engine properly. Give that a try first.
Ed Cregger
Reply to
Ed Cregger

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