starting motor not engaging to engine

hello i am hoping you guys can help me. the bike is a 1980 kz550. when you attemp to start the bike the starter motor spins but does not engage to the engine. if you might know what is caused this please let me know. thanks for the help.

clutch in starter motor shot, would be my guess

thanks, is it possible to replace the starter clutch or do you have to but a new motor.

I dont know that one for sure, I just buy a new one, u could take it to ur local starter/alternator repair guy and see what he says

The clutch isn't in the motor, its in your engine. The starter motor is always engaged with a gear on the secondary shaft which has the clutch in it. This repair means splitting the cases if thats whats wrong.