Should be right on or very close to zero when you turn the key on. What does it do when you start the engine? Does it read low, or does it read the actual RPM?
guageguy,<br /> Sometime while at idle in gear it will register about 200 rpm. At other times it will register about 800 at idle in gear. Sometimes it will go about 3/4 inch below 0. Other times it will stop at 0.<br /> It will only register 4000 at WOT and the engine has had everything checked out. I guess we are grabbing at straws.<br /> I have another OMC guage and its not hard to install. I was just wondering if the tach could be off that much.
If it is off by 3/4 of an inch at 0 sometimes, and you have at least 11 volts at the tach, the tach is more than likely shot. With battery and ground applied the tach should zero out. Hope that helps. Good luck.
