Doing my last renewal with Irv. Did the preflight, including draining the gascolater (the only drain in the system). The Luscombe has two wing tanks fed via separate taps to a tee piece and thence to the gascolator.
Taxied to the clubhouse, parked and found Irv. Got back in, started, power checks, everything OK, took off. At a height of about 20 feet sudden loss of power. Killed the throttle and landed ahead. Found the engine still running at idle so taxied back. Did the renewal in a borrowed C152. Subsequent ground runs showed no abnormality leading me to suspect that there was a small amount of water lurking in some corner of the tank that found its way into the feed pipe during taxying.
Mike