Yamaha AR240 engine RPM's not in sync.

[Ridesteady]

I am having RPM sync issues when I get over 3,000 RPM. The mis match is 500-1000 RPM lower on the port side engine.
When inspecting the APS i am slightly out of spec
APS 1 = .93 kohm closed and 4.67 Kohm open (out of spec)
spec range is .5-.9 Kohm closed and 3.75-4.35 Kohm open
APS 2 = .8 closed and 4.45 open (with in spec)
spec range is .35-1.05 closed and 3.6-4.5 open

could the APS 1 being slightly out of spec cause this?

You might check your APS1 to make sure it is hitting the stop at idle - the voltages look a little high (but not too bad).

That said, there really isn't anything that can "sync" your engines short of something with a feedback loop. That feedback loop can be you and your ears / hands, or it can be Ridesteady. Even if you drove both engines off the same APS (i.e. identical voltages), there are so many electrical and mechanical tolerance / manufacturing reasons that engine speeds will be different, particularly across the RPM range.