YFZR build tip #3

How-To: Install Yamaha's GYT-R tether kill switch on the YFZ450R

Installing a tether kill switch on an ATV for racing applications is often more complicated than it needs to be. This post will explain how to install a tether kill switch on Yamaha's YFZ450R with two products that make the task quick and fairly painless.

The first, of course, is Yamaha's GYT-R plug-and-play lanyard (tether kill switch). The second is Tarantula Performance Racing's new Tether Kill Switch Mount. The GYT-R tether kit includes a wiring adapter that plugs the kill switch directly into the stock wiring harness. The TPR tether mounting bracket makes room on your handlebars for the tether without shuffling levers.

Step 1: Remove the front plastic and gas tank, and mount the tether to the TPR mounting bracket. Then bolt the bracket in place where the stock parking brake lever bolts on top of the stock clutch lever. (In order to use the TPR bracket, the stock parking brake lever must be removed and the stock clutch lever used.)

Step 2: Next, you'll want to thread the two wires leading from the tether switch down the steering stem, through the frame and up alongside the main frame rail beneath the gas tank and alongside the quad's main wiring harness.

The longer, ground wire should be fed through the frame and along the sub frame and air box to the negative terminal on the battery. Be careful to feed both wires through spots on the chassis where they won't experience excess rub, which can cause wear of the casing and eventual exposure of the wire itself. The "hot" wire should, once you hit the fuel
injection assembly, be fed down behind the cylinder towards the countershaft sprocket.

Step 3: Connect the ground wire to the negative terminal on the battery.

Sounds easier than it actually is. For racers whose quads have some brand of FMI tuner, that module also has a ground wire on the negative battery terminal. Two additional grounds combined with the stock wiring harness ground makes for a crowded terminal post and makes it difficult to thread the bolt through into the fix nut. To solve this problem, we cut a small piece of foam to place beneath the locking nut in the battery terminal, so the lock nut is always within reach of the bolt despite the excess ground spacers on top of the terminal. This allows for easy removal and installation of the battery.

Step 4: Now you can use the wiring adapter included in the GYT-R lanyard kit to plug the "hot" wire from the kill switch into the quad's main harness at the ignition pick-up harness just below the fuel injector. Be sure to use some dialectric grease on these connections to keep water out and insure a strong connection.

After connecting the lead kill wire to the adapter, we crimped the connection and then used electrical tape to further secure the connection. The white plug-in connectors were secured with zip ties. We also made sure to use dialectric grease on these connections.

At left, we used dialectric grease on all the connections. At right, we secure the lead kill switch wire to the adapter harness in the GYT-R kit before finishing the connection.

The adapter harness plugs, at left, connect to the YFZR's main wiring harness via two male and female connectors. The harness connection is shown completed in the photo at the right.

Step 5: Wrap it up. Once all the connections are made, now you go back and secure the wires to each other and the stock wiring harness using electrical tape. Two or three quick wraps in a few spots should do it. Be sure to allow a little slack in between each connection. If the wires are too taut, they could snap or cause a broken connection if one gets caught on something while riding. Make sure the wires don't bind when the handlebars are turned fully to the left and right.

That's it! You should now be ready to ride and race in most sanctioned events that require the use of a tether kill switch. And we just made that installation easier thanks to GYT-R's tether kit and Tarantula Performance Racing's new Tether Kill Switch Mount.