My 2007 S40 will not start up and I am not sure what the problem is.  Out of the blue, tried to start the bike, pushed the starter button all I get is a click and a knock but the starter does not turn.   The Headlight, green light and break light is working, so maybe not the battery.  What should I do?   Any help would be greatly appreciated.
Thanks

Doubtful if it is a teeth meshing concern as they are constant mesh with a one way clutch on the cylinder side of the flywheel. If it clicks, start looking for a loose or corroded battery + and - cable termination, or other electrical connections, switches. Look at the wiring diagram at the safety switches on the starter solenoid control circuit and see if one of them looses it connection when voltage is applied and current flows. Max