Starter works, but doesn't

[Coops.N.94]

I have an issue where my starter spins, but it doesn't sound like the engine is turning over, but it absolutely is turning the gearbox over. Any ideas if something other than the starter could be at fault?

[VStar650CL]

Not sure what you mean by "turning the gearbox over". A bad Bendix drive in the solenoid will cause the starter to spin but not engage with the flywheel. A broken flexplate (flywheel) will cause the flywheel to spin but not turn the crankshaft.

[Coops.N.94]

By turning the gearbox over, I mean that leaving the car in gear whilst staring it, the car tries to move, indicating that the starter is engaging with the flywheel, and driving the road wheels through the gearbox.

[VStar650CL]

If the transmission is connected but the engine isn't, that sounds like the flywheel is sheared or broken away from the crank. It could even be a broken crankshaft.