I've got a few troubleshooting methods,for the starter and relay.
A little unorthodox, but they they are quick.
Make sure the transmission is in neutral.
First remove the fuel tank, depress the starter button with the key on, locate the relay that clicks when you do activate the start button.
If you press down on the top of case of the relay, you can close the contacts of the relay manually.
If the starter is good, it should start to rotate like you're trying to start it.
Second, remove the relay, and use a heavy gauge wire to jumper the metal contacts that the relay connects to in the socket/holder, these should correspond to the large diameter red and large diameter black wires.
When you do this, the starter should rotate, you don't even need the key in the ignition.
I had a starter relay that would click when the start button was depressed, but the contacts in the relay were not making contact, I removed the cover off of the relay, and adjusted the spring return mechanism of the arm that had the electrical contact, and it started working again.
To check the starter button, with the start relay removed, put the red lead from a multimeter to the electrical contact in the relay holder that has the brown and yellow wire crimped to it, the other black lead from the multimeter to a ground, or earth.
When you push the start button, you should see 12 volts, or whatever the battery voltage is on the multimeter display.
Hope this helped, more than it confused !!