Friend with a Glastar/O-320 and I went for a flight this morning. He warmed the engine for 15 minutes (oil was 90 degrees), did a normal runup without problems, and had full power going down the runway. On initial climbout at approximately 200' AGL, the engine went smoothly from full power to no power in about 2 seconds. He lowered the nose and pulled the throttle back to prepare to land on the remaining runway. Once the nose was lowered, we both knew there was not enough runway to land on, or to even touch down on, so he pushed the throttle in and the engine went to full power. We climbed out and brought it around and landed. There was some light cloud layers/fog around us at ground to 300' or so but none in our flightpath. Conditions at takeoff: KFLP 111355Z AUTO 00000KT 10SM CLR 12/09 A3018 RMK AO1 Could ice do this? He didn't use carb heat during the runup. Water in the fuel? He did sump as part of the preflight. Fuel starvation? He had 11 gallons in the left tank and 5 in the right, and both were feeding (both were in the ON position combining into one line and onto the carb). Each wing tank also has a gallon header tank. There is no pump on this plane, it is gravity only. He has flown with less fuel so it is unlikely both tanks unported. Your thoughts are appreciated.