2 smoke engines are cool. Will mostly run off and leave a 4 cycle engine of the same size once it gets into the power band.
Guess they faded into history on motorcycles due to: fuel economy, idle smoothness, smoke, sound, what else? Oil mixing was a bit of an issue because they needed more oil at hard acceleration that at low speeds. Hand mixing had to be made at the wot level which causes excessive smoking at regular rpm. Oil injection mostly solved the issue but they all smoke some. Theory is that they don't last as long as 4 cycle engines due to the better oiling of the 4 cycle but I have had some that seemed to last forever.