Start simple and cheap and work your way up: Starter fuse OK?, Check starter relay; Relay OK: Check Starter switch (yes, they do go bad or get broken). Also, check the CONNECTORS....sometimes thes get loose or a wire gets broken from incorrect routing, or somebody pulls on 'em too hard and breaks a wire. If the bike bump starts, you are getting juice to the EFI and Ignition, so it's something in the STARTER CIRCUIT. Sounds like a loose wire or burned out/loose fuse or relay. I once had a Honda that wouldn't start; when I took apart the handlebar starter switch, broken plastic pieces fell out.