Micky,
The needle is a light "push on" fit on the tapered shaft - just bumping it
while cleaning shouldn't move it. But to get it back to normal, remove the 2
screws on the back and remove the tach mechanism. Carefully hold the large
silver-colored metal plate and you'll be able to gently move the needle down
enough so it will rest wire stop.
While you're at this stage you can calibrate it by attaching the tach cable
to the tach mechanism and run the engine up to 2500 RPM (or 3000) using a
good electronic tach. Record what your tach read at that RPM. Shut down,
carefully turn the metal plate until the needle gets to where it was reading
when the engine was at 2500 RPM. While holding the metal plate at that point,
gently turn the needle to 2500. Push down a little as you turn the needle so
it will be a good fit on the shaft. Recheck and adjust.
Sometimes the magnet or return spring (or both) get weak and the guage
won't read right, or if it does, won't sit on the stop. I suppose you could
drill out a little weight from the counterweight in the needle, but I've never
tried it. Find the best compromise in accuracy and have fun. Good luck.
Jeff
'74 CF13816U
----- Original Message -----
From: Mickylong@aol.com
To: FETNERJ001@hawaii.rr.com ; 6pack@autox.team.net
Sent: Tuesday, June 03, 2003 10:11 PM
Subject: Re: Dismantling a tachometer
Jeff and others,
While we're on the subject... I recently removed the bezel and glass on my
tach while out of the car to clean the face and now notice that the needle no
longer rests on the thin wire stop. Knowing that it's likely that I did
something in cleaning the face to dislodge normal operation, is there
something I can do to reset the needle against the stop?
I did not remove the face or screws on the back of the tach, just the bezel
and glass.
Any suggestions?
Micky Long, Atlanta
72 TR 6
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