What exactly do you want to know? Again, the engine is almost certainly an EA300 or 330, the only problem I have with the identification is the cylindrical heat exchanger
; most of the ones I've seen are rectangular.
Typically the way these are cooled is passively; the fresh water in the H/E is circulated via convection. The electric pump
just circulates raw water
through the HE and the exhaust
A manual is available here;
but it doesn't include the HE.
A call to a knowledgeable Kubota dealer might get you somewhere regarding specifics on who services or provides specific parts
. It appears that they are still available; I bought a liner, rings, brgs etc. in 2013.
The only other question I'd have is if the output is correct, as the engine is only rated at 7.5 hp. It is entirely possible that someone cobbled the generator together from available parts
; there are many such examples on the utube.