I suspect that mini engine has a glow plug that ignites the fuel. I
don't beleave I've ever heard of diesel operation without fuel
injection, you just couldn't control the point at which the fuel begins
to burn during the compression stroke. Be leary of light weight
diesels, the internal pressures that a diesel has to deal with are much
higher than that of gas engines. That's why industrial diesel engines,
like generators on boats, tend to last so long.