Still live:
https://www.c34.org/wiki/index.php?title=Diesel_Engine
Regarding/Listed:
M-25, a 3-cyl, 21 hp engine, was installed on the the early models.
M-25XP (3-cyl, 23 hp) became standard in 1988.
M-30, a 4-cylinder producing 28hp, became an optional engine about the same time and is...