The O.S. .72 FS SHOLD fly the Four Star 60 with authority... you have somehting wrong with how you are operating the engine. Wrong prop, wrong fuel, bad adjustments....

A .61 2-stroke with the right prop and the plane will do any maneuver it was DESIGNED to do... thats about everything in Sportsmand and Intermediate Pattern competition schedules.... and more. It may not be good for precision at some of them, but it will do them. (infinite inside-outside vertical 8's which requires GOOD power... {thats stacking an inside loop on top of an outside loop.... now do 10 of them without stopping.})

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Where this trend to stick excessively oversize engines on every model came from... got no clue. It is often harmful to the performance of the aircraft in the speed range it was DESIGNED to fly.

Part of it is the fault of scale warbirds.. when you build a Top Flite Gold edition warbird by the plans and cover it with MonoKote, the .61 2-stroke is PLENTY. when you fiberglass finish it, add a DETAILED scale cockpit and put 16 coats of assorted color paints on, then hang the thing with all kinds of detail items... you need a 1.2 to get the lead sled off the ground.

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The proper guide is... the listed engine on the kit instructions. Build LIGHT if you want it to be fun to fly. If you want to compete in scale contests, don't expect the model to be fun to fly.