It is a 22kw, 2.4 litre, Mitsubishi engine, good chance it is an 1800 RPM unit, LP or Nat. gas. 300 hours is not much run time for a liquid cooled unit. Depending on the history, maintenance, and selling price, it might be worth looking at. Those units are pretty solid, very little engine trouble, as always it's the electric/electronics that give us trouble and can be difficult to diagnose if it is an uncommon problem. You might be able to get it to fire on a portable LP tank but it needs to be regulated to 10" - 13" w.c. pressure, can't run tank pressure to the genset without damage/no start.