factory tach calibration

[wally426ci]

since ive rebuilt the car, ive come to terms that my tach is "off" is there a way to get it to be accurate? i hooked a dwell/rpm meter up to it and that would read like 975 and my car would be reading 12/1300..... oh and it seems to be in fractions, its not as easy as subtractin 300........

 

[miketyler]

The movement does have adjustments. You will need to remove it to get at them. There is a very fine recoil spring attached at the front and rear of the movement. It is mounted to a terminal board which when moved, adds or subtracts tension or "moment" to the needle shaft. Before you start tearing into it, make sure your voltage is correct feeding into it. I ended up using Greg Garners upgrade tach board. Was easy to install and calibrate. You probably are already aware but these tachs are not as "lively" as todays technology tachs.

http://rt-eng.com/mediawiki/index.php/RTE_67-74_Tach_kit

He has some test info including an output voltage table that you should find helpful. Its located on the last page of the tachboard manual

http://rt-eng.com/mediawiki/images/f/f9/TachManual67-74.pdf




   

[wally426ci]

if the voltage isn't the problem, is there someone who provides this break-down service? I'm all thumbs 

Thanks Mike!!