A 62cc Zenoah chainsaw conversion, same cylinder and piston as the G62 sold for airplanes, weighs 3 lbs, 12 oz, with ignition inside the mount, NGK CM6 spark plug with a DA shielded cap..I just made a deal with Dave at DA to use his caps so with the CM6 spark plug they're lighter than the RCJ7Y normally found in a G62.......I have one here, just weighed it, that's what it weighs without a 2 ounce battery and muffler...I use an old spring scale, but it can't be too far off.....The chainsaw 62 has a magnesium alloy crankcase and a slighty smaller diameter crank....They were sold as Green Machines and now as Red Max...
If you want thrust you can use a 24-8 prop, slower but stronger...
A stock G62 mag engine with a Bennett mount, no muffler, no spring starter, weighs 5 lbs 2 oz on the same scale...20 oz more....1.25 big lbs...