Cummins 6B Sync. question

[Oscar]

A "new to twins & diesels" question. Is a 500 RPM difference between the port and starboard engine to sync. considered normal? On my 1st. adventure aboard my 4100 sca tried to run at 2,000 rpm but had to kick the port engine up to 2,500 to sync. Thanks for any insight yu can offer.


Oscar

[Glenn111]

Those analog gauges are generally not accurate. Either the tacks or the sync gauge may be "way off". I suggest you sync by sound as your gold standard. Tapping the gauges gently may result in improved accuracy. Of course, purchase a laser digital tack gauge from any big box or electronic store to get a precise reading of engine rpms. Might try removing/cleaning the gauge inputs to the helm console. Tack pick-ups are on on the flywheel, port side of the engine for adjustments.

[Oscar]

Thanks for taking the time to answer, glad it's likely as simple as gauge inaccuracy and not something like droopy trim tab syndrome that would cost thousands to diagnose and cure. I'll be back on the boat this weekend tapping & cleaning. Once again, thank you very much.