It was the timing. We took off the engine hatches today and ran a timing light with the motors turning 3900 rpm. The starboard was at 22* total timing and the port was off some but not as bad. We set the total timing to 38*. The boat now does 4300rpm port motor, 4200 starboard and 60 mph. The starboard throttle linkage doesn't go as far as the port but the carb seems to be opening up. We may recheck the timing on the starboard motor. We're on the right track now though. Thanks for the input.

38* is too much timing for what you have. Back it down to 34*. I doubt you will see any performance loss.

BTW That is still not enough rpms at WOT. You will prob want to drop down 2" in prop pitch which will give you about another 400rpms.