701 tach install
For some reason, this quite expensive bike doesn't come with a tach. Here's how I installed the Koso D55 'GP Style' model which goes up to 9000 RPM, which is perfect for this bike. It also includes an oil temperature display; a sensor for that isn't that hard to install on the bike. Although I've installed it on a Husqvarna 701 Supermoto, it should work the same on a KTM 690.
Behind the face mask are an always-on (aux1) and switched (aux2) power plug, just like the tach needs. I used short wires to connect these to Wago clamp connectors, that way multiple accessories are easy to wire up.
Tach signal pickup
As this bike uses stick coils, you can't just wrap a wire around a spark plug lead to get the RPM signal. I elected to get it from the inner spark plug. In the bike's wiring diagram, it can be seen the coils use a KTM 'AS' connector, part number 000700000AS. The actual name for these is Furukawa FW-C-2F-B (female) and FW-C-2M-B (male), and they're easy to get from China. I built a splitter that goes from one male plug to two female ones. The male and one of the female plugs are connected as usual. The tach comes with a long wire with a bullet connector, I added a second male Furukawa connector to that to plug into the spitter.
Tip: Do not power on or start the bike with one of the coils disconnected. I don't remember exactly how I did it, but I got a Check Engine light that took a trip to the dealer to clear.
The coils use the 'AS' connector in the KTM Spare Connectors catalog.
I forgot to take a picture of the splitter before installing it...
Oil temperature sensor
The modern LC4 engine still comes with fittings for an oil cooler, from its Dakar days. There's one behind the starter that can be used. It takes a m10x1.0 temperature sensor (which is different than the sensor that comes with the tach).
I added an extra crush washer so the sensor wouldn't protrude too deep into the oil galley, but that doesn't really seem necessary from other people's accounts.
Mounting the tach
Initially I used the little v-bracket that comes with the tach together with a clamp that's meant to hold piping. Later on, I 3D printed a nicer holder that keeps the tach a bit lower, for a cleaner look. The 3D print file can be downloaded here.
The original tach mount.
The new tach mount.
The new clamp can be installed without having to disconnect the tach wiring.
Bonus: GPS mount
I also 3D printed the GPS mount which can be seen in the photos, it can be downloaded here. It makes use of the asymmetric handlebar clamp to keep everything in place.