Mine did this as a result of a bad wiring harness ground at the engine. Dave
Sent from my iPhone > On Jul 26, 2022, at 7:04 AM, David Knecht via CnC-List > <cnc-list@cnc-list.com> wrote: > > Yesterday, I was motoring and noticed that the engine tachometer was acting > strangely. It would read 4000 rpm for a while and then drop back to 2000 rpm > (roughly correct). Then it would go up to 3000 rpm and hold there. It kept > bouncing around while the actual engine was steady, so it was just the tach. > I have no idea where the data comes from, what would cause this, and whether > to worry about it. The engine is a Universal M4-30. Thanks- Dave > > S/V Aries > 1990 C&C 34+ > New London, CT > > <pastedGraphic.tiff> >
