the 195 is rated at 2000rpm at ~8.8kwatt or so
it will carry a direct drive st head at a bit over 7kwatts
therefore at about 1000rpm it will carry about 3.5kwatts, but just barely
because the engine is running at about the low limit of its design
it runs much better with 1200rpm being the low rpm limit, and make abut 4 kwatts dependably
you cannot run it slow enough to make only 2.5 kwatt electrical in my opinion
the balance shafts are optimized for ~1500 rpm in my opinion, 2000 is a bit fast and 1000 is about as low as you can go
and not have it beat/shake itself apart.
hope this helps
btw, there are idi and di versions of the 195, there may be some differences between the two types in how low rpm they will run?
bob g