I have twin 350 Crusader engines. The starboard engine runs fine. The port engine runs good for a while, but then looses RPM's. If I'm running at 2400 it drops to 2000, then to 1800, finally to 1200. When I increase the throttle the RPM's run up and down and then the engine stalls. When the engine is in neutral there is no problem holding the RPM's and the throttle works fine. I have read various responses to similar posts, but most did not indicate that the engine ran fine in neutral, so the responses had to do with fuel filters and carburetors. I read that it might be that the hub has spun out of the prop, how difficult of a repair would this be. Any thoughts?