[p739]

Is it possible to synchronize dual marine engines to run at the same rpm from a single throttle lever via speeduino engine management. Controlling 1 engine and then having the other engine match the rpms.

[PSIG]

Not currently. If implemented some day, most of the system would be external as auto-throttles, referring to Speeduino data for their operation. Your focus would be that auto-throttle system, possibly based on existing ETB/TBW boards out there, with a controller using data to sync. Examining some marine and aviation sync systems may be helpful to concept. Good luck, and let us know what you find!