Initally I said the starter motor wouldn't stop spinning...... Could that
have something to do with the solenoid not letting go???

I second the notion..

replace the solonoid switch, and also see if the teeth on the flywheel are worn
on the bottom side where the drive clutch will enguage it. sometimes the
blunted flywheel has the gear worn where the drive clutch can't engage because
it's "jamming" in the teeth, and can't engage smoothly and will "lock up" the
drive clutch so the mmotor cant't spin properly.

Tim

Tim