I'm assuming that the 796 uses the same speed sensor as my 1100 Evo, in which case it will be a two-wire unit no. 28 on the wiring diagram.
If you have a multimeter, it's a simple job to check. Place the black meter wire on the black terminal and the red meter wire on the white terminal. Set the meter to AC volts (NOT DC as you might expect because the sensor output is in the form of a sine wave). Spin the rear wheel and, if the sensor is working, you should see a voltage increase on the meter - the faster the wheel, the greater the voltage.