Ums-7-50
I have the UMS 5-55 and the Glow 7-35. I have seen the 7-50 run and it is a good engine. Some of the UMS's carb have too large of a choke area and when tuned for max power at full throttle run too rich in the mid throttle positions. Experiment with tuning the engine at lets say 3/4 open and tune for max performance (after break in). This can help make mid throttle with a better fuel mixture. Often at the lesser carb opening and retune there will be little to no loss of power due to as previously said the choke areas tend to be too big. I suggest a 22x10 prop. -Tom