Re: 1987 evinrude 88 spl
You should have a rectifer on that engine. That device does two things: charge the battery and pass a pulse count signal to the tach. Usually when the tach starts to act up, it's a sure sign the rectifier may not be re-charging the battery. The fact that it's hot may be an indication of failure. Check to make sure your battery leads are really tight and in solid contact with the battery terminals. (If they are loose, or corroded, the voltage needs to go somewhere...) Sometimes the tach acts up just at the top of the rpm range, so you may not have noticed...but really any tach irregularity adds a clue to your problem. It may well be the rectifier that's giving it up. They are not real expensive.. If it's really old (or original) probably time to replace it.
