We have a single cylinder Kubota DC genset that is finally working on Clairebuoyant. It was sold by Jack Rabbit Marine, but was clearly marinized by Phasor. There is a shelf on top of the heat exchanger that supports a small pulley driven Johnson pump of maybe 2-3 gpm. Phasor could probably source the shelf, pump, and two pulleys. The drive pulley fits inboard of the alternator drive pulleys.
I think there is some confusion with the larger multiple cylinder Kubotas which mount a Jabsco or Oberdorfer on the front of the engine. The small one cylinder horizontal will not fit this pump, but I’ve seen them at Boatshow with a special pulley mounted on the hand crank shaft that belt drives a pump..
Quent