Prime the carbs with a little squirt of fuel, and they should at least fire up.
If you have some carb/choke cleaner around the garage....pull the needle
valves out, and give it a squirt into the nozzle of the carb. If you have some
compressed air, give the nozzle a blast or two. Reset the needle valves at
about two turns out for a new start.

The carbs and fuel systems must be clean, and the fuel must be good, if you
want to get them running. Put new glow plugs in as well, if you have some.

FBD.