I don't know anything about that gas engine, but I do know that ever light/portable engine I've ever used has leaked gas. Some leak even from wake rocking the boat or just from locking up in the tailoring position.
Keep in mind that if you tip over your engine will exceed 90 degrees and can invoke the safety feature that leaks gas. It might even drip on your head as you unlock your main sail.
You'd be better off with electric engine and charge meter. I don't believe Hobies are meant to be loud sources billowing blue smoke.
I still prefer the paddle but I'm young and hard headed.
Check at this thread from the Getaway section on the Cheata motor mount.