Kubota makes their own diesel gen sets which run at 3,600 rpm.
KUBOTA GENERATORS | PRODUCTS | Specifications : GL Series : U.S.A.
There is also a marine version which is rated at 3,600
Beta Marine Canada - Standard Engines
For satisfactory generator operation, the engine needs to be running on the downward slope of its torque curve so that if it slows slightly under load the available torque is increasing.
Starting to try and run the engine slower means you may be at a point on its torque curve where the torque falls off as rpm's decrease which can lead to a sudden stall.
I apologize for resorting to technical jargon to make a point but it is critical in generator operations.
The torque curve shows a downward slope as it goes from 2,800 to 3,600 rpm.
If you have the engine rpm's in that range and the load on the generator increases as the engine starts to slow down from its 3,600 rpm needed to produce 62 cycle AC, the torque output of the engine increases so it accepts the extra load without any fuss.
If you think it is a good idea to slow the engine down and use pulley's and V belts to turn the generator head at 3,600 rpm, you are now operating on a place on the engine torque curve where a slight lowering of engine rpm produces less torque and this situation quickly deteriorates into the engine stalling.
You need 2 HP to produce 1 kW of electricity. so in your case to turn the HF gen head you need at least 20 pto HP which you do not have.
Yes you can run the gen head with less engine power but not with a stable output.
Some engines are designed with a tapered shaft specifically for powering water pumps, generators etc, If this engine has a tapered shaft it is not the best for your application as lots of fiddling will be needed.
Dave M7040
