do these go bad pretty often and are they exspensive, I've been working on my choke and notice today when the engine was running the tach said 4000 and it was only at idle so i rev it up and back to idle and it came back down but still seems to running high it says motor is running at 1500 now and i know its not. Time for a new sensor?
Thanks for all the info, the funny thing is I went out and fired the boat up and tapped on the tach and it started reading fine, checked the wiring on the back its all tight so sound like I need to find a new tach in the near future thanks again