It could simply be some corrosion. Check all connections in the wiring harness. Look for frayed wires. Unplug and replug the connections several times. If the male ends look corroded you can clean them with a plain old rubber eraser. You can also spray with contact cleaner. The starter button connection could have gunk on it too. Take the switch housing off and spray with some contact cleaner.
Otherwise the solenoid is likely or it could be the starter itself. If there's a local junkyard you can try to get parts from a wrecked bike.
Otherwise the solenoid is likely or it could be the starter itself. If there's a local junkyard you can try to get parts from a wrecked bike.