Here is information that will get rid of the confusion on figuring out what Kubota engine you might have.
The letter before the displacement/model number identifies the number of cylinders.
Z = 2 cylinder engines.
D = 3 cylinder engines.
V = 4 cylinder engines
EA, EB, EL = 1 cylinder horizontal cylinder engines
ZB = 2 cylinder horizontal cylinder engines
I feel the most useful Diesel engines in the present and past Kubota line for our needs are:
EA330 or the smaller bore EA300
Super Mini Series:
Z482
Z602
D722
D902
05 Series:
D905 (some are still out there)
D1005
D1105
D1305
V1505 (4 cylinder)
BG series: (was designed for generator use, will add content later)
Spark ignition engines
SI series:
That is another day