Hi amigos-
I have a 68 camaro with a gm tic-toc-tach. The clock keeps good time, but the tach reads higher than the engine is actually turning by approximately 20-25% (?). I had help in wiring it since I am inept in such matters. It is wired to the coil. Any thoughts on why it is showing higher rpms than the engine is actually turning? Thanks again!
Guy

look on the back side of the tach there should be a hole where you can put in a small screwdriver and turn what is called a potentiometer and it will recalibrate your tach (probably the only hole back there),if you have another tach (any will do)hook it up and verify your settings from both at the same time

Hey, thats sounds like something that even I can do. Thanks alot, Gunny.

Maybe you and I need to switch tachs? My dash tach reads a little low all the time. :(

I wasn't sure if my speedo was off or the tach was off but I checked the speedo with my GPS and found the speedo to be right on. I just checked the tach with an old sun supertach and verified that the dash tach was indeed reading low. I will pull the tach out today and look for the adjustment hole if there is one. It is a 69 tach so that might make a difference. I wish us both luck.

If I can't do it myself, I plan on using "The Tachman" to fix it. If anyone out there has ever used him before, please let us know if you were happy with the job.

-Mark.

I was wondering if anyone has had any luck adjusting there tach.My tach is off by 3-400 rpm and needs to be zeroed as well. I didn't find any adjustment on my 69 tach, but I didn't really know what I was looking for at the time either. Good luck everyone.

I didn't find any adjustment on my 69 tach either. It is going out to the Tachman in a day of two. He gets between $75-$250 to redo them. That's what the Tachlady said when I called. ;)

-Mark.