there were also farm tractor engines that started on gasoline and then ran on
kerosene. Honda Racing kinda did something similar a while back, because the
race rules limited the total gallonage of fuel available to a car. Kerosene
has more btu's per gallon, so (as I understand it) gasoline/air fuel were
sprayed in near the plug (because it would ignite well) and keresene/air fuel
was sprayed elsewhere in the cylinder. I understand Honda dropped the idea
eventually, but don't know why.

BTW, I seem to remember an old CAT tractor whose engine started as a
gasoline
engine, and when warmed up, converted to diesel....could be wrong.

There are some old tractors that use a gasoline engine as a
starter motor. You'd start the gasoline engine and then couple
its output through a clutch to turn the diesel engine, getting it
to start. I guess that was because they didn't carry enough
electrical power to use an electric motor to turn the diesel, or
maybe they did it that way because it's Just Cool.