I run my stinger 120 with a Moki 180. The Moki weighs 41 ounces with muffler and I have to carry 16 ounces of glow fuel. A comparable gas engine would need to have about 40 cc and will likely weight a bit more. But you can run a smaller tank.
With the Moki, I have unlimited verticle. Running a 18x10 prop.