Any el cheapo tach from the auto store will fine. If you can find an old
Dwell/Tach service meter, that works fine also. Both of these clip onto
the wire between the coil and the distributor.

You can also get some newer electronic display units that just wrap a
sensor wire around a spark plug lead. This one is $40, has both tach and
run time meter.
http://www.northerntool.com/webapp/w..._524744_524744
I think you can do better on both price and features but you get the idea.

SteveB wrote:
I need to set a welding machine drive motor at 2300 RPM as suggested by the
Lincoln tekkie until I can get the circuit board and controlling devices
worked on.

Is there a simple cheap tach that I can buy that will just alligator clamp
onto a spark wire or some other easily accessible place? This is a
Continental four banger.

Steve