I can put a motor on any of my bikes in a second a really nice two piston joint. Still a bit gassy but no petroleum, thanks! Those bolt on gas motors are death machines waiting to happen and have no need to exist for any reason. We have motorcycles and we have quality e-bikes no need to turn a bike into something really bad.
If you are looking into suicide please visit:
https://www.crisisservicescanada.ca/en/. We are also here to help in whatever ways we can but they might be able to help better. Keep your chin up and stay alive, death by lawnmower powered bike isn't glamorous.