Does anyone know if there is any way to calibrate the tachometer? Mine reads about 250 RPM high.
Thanks,
Forest
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Yep. There is a small potentiometer on the back of the circuit board that can be adjusted. You have to pull the tach out of the instrument panel, carefully pry the chrome ring off the back cover by prying the little tabs away from the flange of the back cover. If you do this carefully, you do not need to bend the tabs. You can then remove the guts of the tach by removing the screws from the back cover to get at the circuit board.
The next trick is to wire the tach back into the harness and also have another RPM reference hooked up to the system to match the readings. In my case, I have an EFI unit that has a hand held controller and display. A diagnostic tach instrument may work too.
Try to use a plastic or non-magnetic screw driver when performing the adjustment. Magnetic fields throw of the reading.
The next trick is to wire the tach back into the harness and also have another RPM reference hooked up to the system to match the readings. In my case, I have an EFI unit that has a hand held controller and display. A diagnostic tach instrument may work too.
Try to use a plastic or non-magnetic screw driver when performing the adjustment. Magnetic fields throw of the reading.
Jon Haas of Pantera Electronics did both of mine. Both were out. One about 250rpm, the other about 400rpm.
Inquire with him if you need someone reliable.
Inquire with him if you need someone reliable.