https://m.youtube.com/watch?v=ASh5TSdexb8&si=JWYAldJ_BkI7ilYe

Please help. Any ideas on what's wrong ?

 

Sounds like the starter gear isn't kicking out to engage the flywheel. Hard to tell for sure but it sounds like it's spinning but not engaging anything. If it sounds to you like something small is spinning (and then slowing down after you release the key from the crank position), that's probably what's happening. In the old days, we'd replace the starter solenoid but these days, the solenoid alone will cost you almost as much as a new (reman) starter. So most people just put in a new starter.