My Q100 started running very fast with the throttle closed and I had to run the airplane out of gas in the air to get it down[X(]. Naturally I thought it was a throttle linkage problem, but the linkage was fine and throttle butterfly was closing completely. I took the carb apart, cleaned it with carb cleaner, reassembled it, and it still does the same thing. Putting a different carb (Wallbro SDC80) on it solved the problem.

I called Bennett and they said to look for wear on the butterfly due to vibration - but there is none. The butterfly closes completely.

Any ideas? I guess I'll send the carb away for a rebuild.

Mark