XS650 Electronic tach

[afholderman]

I have been eyeballing the Speedo's and Tachs that mikesxs.com has for sale, but want to be sure that they will both work for my GS1000. Now I searched and found the previous post where MrSelfDestruct stated that the speedometer worked, so I am confident there. My question is whether the electronic tach would work on the GS. I understand the mechanical tach's have different ratio's, but the electronic one just reads the pulses to the plugs, so it should be universal, correct?

[salty_monk]

Unless it's adjustable you need to check out the ignition system of the XS....

Our bikes are 4cyl but wasted spark so when setting the tach you need to use a twin cylinder setting in order to get the right RPM... If the XS has a coil for each cylinder then it should work.

[afholderman]

The website states, "Tach functions only with single dual output type ignition coils." So if I am reading that right then that is a no?

[salty_monk]

Affirmative

You need one that can work as a two coil twin (or one specifically for a wasted spark four)

[André]

What year was that xs, my 1975 had a mecanical driven tach.? Just curius.

[salty_monk]

Doesn't matter... they are aftermarket & driven from the coil trigger...

[afholderman]

The site claims they are for 80-84 XS's, to quell your curiousity. Well then, if that will not work then the search will continue. Kinda sucks though, they are nice looking gauges with a nicer looking price.

[Roger P.]

The website states, "Tach functions only with single dual output type ignition coils." So if I am reading that right then that is a no?

No, that is a yes.

One dual-output coil is used with a wasted spark. Otherwise you would need a separate coil for each cylinder and two sets of points, or two separate triggering mechanisms. Older XS650's had two sets of points that ran off the cam, 180 degrees apart, so theoretically they could use a separate coil for each cylinder. Later XS's had a TCI, with one dual-output coil, and a wasted spark. In fact, they can use the exact same green Dyna coil as the GS1100 and others.

Since the GS and the single XS coil both use a wasted spark, the tach should work just fine. The tach won't care about the other coil on the GS, as it is only connected to one. If you tried to use this tach on an XS with two single-output coils with separate points, as some XS owners have installed, it would read half the true rpm, as there would be half the number of firings per coil.

[afholderman]

No, that is a yes.

One dual-output coil is used with a wasted spark. Otherwise you would need a separate coil for each cylinder and two sets of points, or two separate triggering mechanisms. Older XS650's had two sets of points that ran off the cam, 180 degrees apart, so theoretically they could use a separate coil for each cylinder. Later XS's had a TCI, with one dual-output coil, and a wasted spark. In fact, they can use the exact same green Dyna coil as the GS1100 and others.

Since the GS and the single XS coil both use a wasted spark, the tach should work just fine. The tach won't care about the other coil on the GS, as it is only connected to one. If you tried to use this tach on an XS with two single-output coils with separate points, as some XS owners have installed, it would read half the true rpm, as there would be half the number of firings per coil.

Okay that makes sense. I notice you have an XS650 in your sig, so I'll trust you knowledge. I posed this exact question to the people at MikesXS, but they haven't responded in over a week. I guess they don't want potential customer's money that much...

[salty_monk]

Thinking about it I am now inclined to agree. The XS wasted spark coil must fire twice for every RPM & so does the GS one so it should work. Sorry if I misled you earlier!

[afholderman]

I finally received a reply from MikesXS. It was a resounding, I dunno. They were careful to specify that if I buy the parts in speculation for another motorcycle that I get no refund. I understand being loyal to your favored bike, but a sale is a sale. If these will work on other makes and models of motorcycles it would be in their best interest to take note and help out potential customers. I am having problems pulling the trigger, torn between this dual gauge set-up or a Trail Tech Vapor.

[afholderman]

Update: Found out that www.partsnmore.com has the same gauges, mechanical and electronic, and lists Suzuki's under the applications. Also, they're mounting clamps are half the price. Looks like I would be going through them if I go the two gauge route. My tach cable needs replacing anyways, so I would most likely still get an electronic tach. Anyone have opinions on mechanical versus electronic?

[landshark]

I am running an Acewell, it seems pretty good so far. I havent got the Tacho set up perfectly.
I could be wrong, but i dont think you will get an electronic tacho that works as well as a mechanical.

[afholderman]

I am running an Acewell, it seems pretty good so far. I havent got the Tacho set up perfectly.
I could be wrong, but i dont think you will get an electronic tacho that works as well as a mechanical.

No you won't. They have an electronic and a mechanical model available.

[Roger P.]

Electric tach on my 900 Seca worked just fine. I'd take that over a cable driven one anyday.