While running at about 48-4900 RPM, the port engine on my 200 occean pro cut back. I then throttled back the starboard so they each ran fine at 4400 RPM. On the way home I tried to Run the port to match the starboard at 5K even and it would not get there.The throttle on the port side lever ran 3 inches past the starboard throttle? It idled fine pcked up from 0-4500 RPM very well. I fear cylinder problems but theis sounds more like stator or plug wire/fouled plug. I'm curious about cable stretch? Is this possible as well?