I usually run 36psi on front, 42psi rear.. also, psi may be dependent on what tires you have.
Could you share some more details…
Mileage?
was it garaged?
Has the HES been replaced/ upgraded?
Tire age and condition?
IIRC, these were essentially a R1100, but with 850 jugs. These were relatively rare in the states. I think they make a nice roadster, and if as reliable as my 1100 oilhead, and nice ride.