Small diesel engines can and do power boats ... Unlike a minibike, a motorcycle is made for legal highway driving. Furthermore, diesel powered motorcycles are exceedingly rare, but do exist.

In the comments section of Erin's post on the diesel motorcycle ... And could such an engine also be appropriate for small cars? I don't see a reason why not.

[Alex] has been working on a diesel motorcycle project for a few months ... for something [Alex] describes as an industrial Chinese engine, a modded Honda Superdream, and a few Royal Enfield ...