Briggs and Stratton 450 - Starter recoil slips

Hi I'm new here...
I've got a mower with a briggs and stratton 450 motor.
When I pull the cord I can feel it engaging and locking on and starting to turn the motor, but when I really start to pull harder, something slips with a harsh ratcheting grinding sound, as if the starter was losing its grip on the motor shaft. Hence the motor doesn't start because I can't get a good pull on it.

Anyone know what the problem could be ?
Do I simply have to replace the whole recoil assembly?

Thanks!

Most likely the starter pawls are worn. Remove the blower housing/engine cover and take a look. Should be able to just replace the pawls.

Thanks I'll try to remove it tomorrow and see what I find...