I am looking to install a Tach on my 650. I emailed autometer to see if they have one that will work on the 650v-twin. The tech from autometer asked "Please send your manufacturers information about your ignitions pulse per rev and the size that your quad can accept". I cannot find this info in my service manual. Does anyone know this information?
Thanks

 

traxterman,
Are you talking about the tiny tach? I saw that before, thats not what I am looking for. I want a round tach with a needle gauge, easy to read at a glance. I dont like the digital readout, to hard to read at a glance.


I like my 650 a lot so far, it only has about a 100 miles on it. Hopefully I will have more time to ride it this spring than I did last fall. I wish it would snow here so I could take it out.

 

They (Autometer) has a Pro-Cycle line of Tachs for 1 and 2 pulse ignitions. That means 1 or 2 pulses per 360 degree revolution. A two-cylinder 4-stroke would fire once for every revolution and a four-cylinder fires twice. For the 650 V-twin, one pulse ignition is the answer but there is another problem. The 650 has a control unit, ignitor, and two coils. They may not have a Tach that will hook up to this type of ignition system. You can read the connection info on their website under tech tips/FAQ and then select the pro-cycle tach wiring info pdf file. I think the problem is that you have to connect the Tach in the system before the ignitor, because the ignitor probably has two separate outputs, one for each coil. If you use a single coil you will only "see" one firing per two revolutions and therefore read half the correct RPM. You also need to make sure the place that you connect too is a 12V square wave output. If you try to Diode-OR both coil lines you run the risk of cross-firing the engine. You may want to read the info on C.O.P. (Coil on Plug) ignition systems on their website. I will look at the quad schematic tonight and see if it shows the connections. The Tiny-Tach avoids this because I think they use a wire wrapped around one of the spark plug wires and use the principle of magnetic induction. I don't like the digitals either, except for setting idle speeds. Let me know what Autometer tells you.

 

Prairie633,
I tried to send you a private message but it did not work, and I need your help.
I just got a tach for my Mojave. It is not reading any RPM's though. You seem to know a lot about this so would you be able to give me information on where to connect the green wire (Picks up the pulses)? Thank you in advance.