Great Plains Logo & Address


To install your tach to a Slick Magneto, remove the M2266 harness from the magneto by removing the 3 screws that hold it on. Between the number 1 spark plug wire and the number 4 spark plug wire, drill a small hole about .075" in diameter. Take the pickup wire from the tach, insert it in this hole. Grab the #1 spark plug wire from inside the cap and pull it. Wrap the pick up wire around the unshielded portion of the spark plug wire between the cap and the aluminum furl that holds the wire in the cap. 2 turns is enough. Use a dab of silicone seal on the small hole in the cap when it is installed back on the magneto.

To install the tach to a Vertex Mag, Distributor or Secondary Ignition System, simply wrap the pick up wire around any spark plug lead. Note: spark plug wires that are not shielded cannot be touching each other. The secondary false signal will cause the tach to read improperly. Likewise, when going through baffling, the wires must not touch the pick up spark plug wires. Wires must be insulated from the baffling also as the baffling will cause a false signal to be transmitted.

Photo 1

  Drill a 1/8" hole through the mag harness cap as shown.

  Photo 2  

Wrap the wire around the unshielded portion of the spark plug wire.  Reinstall the cap when done.

Note: On 4 cylinder engines that use a Mag, Slick or Vertex, or Distributor, a Model 4C is needed. If you are sensing off our Secondary Ignition System that uses 2 coils and dead fires on a cylinder, you need a Model 2C.

Warranty: Any warranty is direct from the manufacturer, not Great Plains Aircraft.

Return Policy: Any tach that has had the wires cut, holes bored out, defaced or exceeds 10 minutes of operational time is not returnable to either Great Plains Aircraft or the manufacturer for exchange. Some customers have ordered the wrong unit, run it for 10 to 15 hours, modified it, defaced it and then decide they don't like it, or it is the wrong unit for their aircraft. We are glad to exchange it early for the correct unit as long as it is in the original condition.

Go back to Tiny Tach Order Info

Go back Shopping Cart Index

Go back to Instruction Index