Gearbox wiring + other Problems?

So, I have a brand new JG gearbox and I put in a weaker spring. Now when I connect the battery and the motor up (The motor gear is outside the gearbox) the motor starts going straight away, without me pulling the trigger. BTW This wiring came with a mosfet fitted but it was broke so I am connecting the battery as normal and the third little wire for mosfets is left loose.

And When I tried it with the mototr in the gearbox (I actually did that first thinking it was working fine) All that happens is the motor makes a sound as if it is turning bu the piston won't cycle.

Any suggestions? Thanks.