[Thumper]

Regarding a replacement solenoid...

You probably don't need one, but-

Amazon and ebay have lots of dirt bike solenoids. Virtually any of them will work. Choose one that fits your mounting setup (fits in a rubber piece, or mounts to the frame...).

AND, solenoids come in two main types. Both types have the two main posts to connect to the battery, and to the starter motor, and a third connection from the starter button. some have another connection. Get the one that matches your original solenoid. They cost $10, more or less.