No, you are not that underpowered. it will fly fine. I doubt it will "Hang" on the prop, but let us know how it goes. My 1.20 magnum 4 stroke is not as powerful as a saito or OS, but it barely hangs on the prop. The Tower .75 is a very fine engine. I wouldn't ever buy a .46 from them, but I have heard/seen very good things from them.