It’s not gonna be the balls or the locking interface (where the balls engage the pockets and make the whole thing turn) that’s really at fault.
It’s gonna be the crankshaft extension that fits inside the hole in the ratchet (the thing with the square profile). The crankshaft extension needs to be polished clean (steel wool and emery cloth, etc) and the inside of the ratchet knob as well. Dang, what are the proper names, anyone know?
If the whole thing hangs up and drags while the engines running, it’ll spit the guts and the rope out.
The ratchet itself is sintered metal so it’s porous and has a degree of lubricity on its own.
Use several drops of 30 weight motor oil squirted in the small hole on the end to keep everything in there copacetic.
You could salvage the balls by polishing them and cleaning the rust out of everything...
The whole recoil assembly is fun to put back together.
---------- Post added at 04:38 PM ---------- Previous post was at 04:21 PM ----------
That video is on point...
but only his description of the issue is good. His idea to put the spring in first and then the pulley is so difficult that it’ll probably have you pulling your hair out after a few tries.
I’ve got the factory instructions somewhere, plus they’re in the Briggs L head manual that’s out there in cyberspace and probably still in the site FAQ or links section.