I bought a gen 9 gearbox for my gen 9, when I got it, semi auto was just another full, auto, they sent another, same thing. I installed the gearbox fine, and made sure the fire selector and selector plate where on the same settings, also tried miss matching the settings but that obviously didn’t work. Also ran it without having the motor installed, just had it wires and sitting separately. Same thing, no semi. Just checking that I haven’t done anything wrong. I’ve reinstalled gearboxes perfectly fine before using the same method so I don’t think it’s me. Cheers.
Where did you get the replacement gearboxes?
Sounds to me like they are not genuine (counterfeit) and dont have the genuine features?
Just off eBay, I think that may be the case as well?