Tokyo marui electronic blow back G36 AEG

I got done though it was my fault for not asking more questions. Bought a 'brand unknown' F2000. Took a risk thinking it'd maybe be an older Cybergun F2000. One I got it, I found it was a very old JLS FN2000 which uses a modified V2 gearbox - the gun works as it should but the gearboxes are weak. Apparently people have...