The main cause for this is that the gauge ground wire and the sender ground wire are not connected to the same exact loction. For best results connect the gauge ground and the sender ground to one single grounding point. Do not daisy chain or jump from one ground to another. Simply have both leads go to one single ground lug.

Some models have a "loop" wire on the back. This is so the tachometer can be used on two differnet engines. Cut the loop wire, separate the ends and tape so they do not short out. This will cut the reading in half. Not all tachometers have this loop wire. Check the directions and take a look at the back of the tachometer to see if you have one. Part numbers ending with a -2 ( i.e. 2AT3-2 ) are usually the ones with a loop wire designed to cut the reading in half. We have another tachometer that is setup for old lighting coils or Ducatti ign. This requires calibration for 2 or 6 imp/rev so the same loop idea is used on these too. But instead of the reading being double it is 3 times. Tachometers ending in A-2/6 ( i.e. 2AT8A-2/6 ) are these types.

The reason we sell senders separately is because we have several options that will work with a varity of gauges so to list all the options with all the gauges it would be a very long list. So select your gauge then select the appropriate sender that fits your application. i.e. plug or pipe diameter, thread size and depth of hole etc.

All of our gauges can be lit using our lighting kits. Many of our customers choose not to light their gauges for a variety of reasons. By leaving these off of the gauges you save a few dollars unless you require them then they are easy to add to your order.

In most cases yes we can repair your older gauge. However in some cases we simply can not get the parts for some of these old items. Anything older then the 70's probably not repairable. Contact pete@westach.com first before sending in your older unit to see if it might be repairable. And to get the correct shipping address. We have moved so do not send anything to the Sonoma address.

Sorry we no longer make, sell or service any certified gauges or senders. This includes but not limited to K28, K29, K30, K31, K32, K33, K34, K35, K36, K37, K39 systems. Along with any 713- ( thermocouples ) and related components.