i have an 89 70 horse johnson the tachometer doesnt work above 3000 rpms in a barrel without a load it works fine i have 13 to 14 volts at the battery depending on rpms it is a brand new tach with new wiring set on 6p have checked grounds. with the boat in the water at about 3000 rpms it drops back to zero have not had a chance to check voltage while the boat is moving is it possible a bad tach? any other ideas ? im lost.
