Electro 35 - Self Timer Doesn't Wind All the Way

I've got a Yashica Electro 35 (mint condition) except for the self timer. It doesn’t wind all the way. It goes a little over 1/3rd of the way through and stops. If I let go from there, it unwinds just fine.

If I keep going, I can hear the gears inside jumping teeth and if I let go afterwards, it won’t move until I push it back.

I want to avoid going to camera repair shops.