My G&G upgraded M4 420 fps don't shoot
 

My G&G M4 (full stock) don't shoot, even with a new motor and a fully charged battery.

My friend have upgraded it with a mechbox that have an m120 spring.

The battery is a Ni-Mh 9,6 volts 1400 mAh nunchuck (compagny is ''grepow'', sounds a little cheap).

When I try to shoot with my airsoft, the battery wires are becoming hot, and the motor seems trying to work, without succes.

Did I must change my battery or the voltage of my battery ? Or something else ?

Please help me !

I had the same problem, with the wires becoming hot. The battery G&G supplies you is crap, you now have to go out and buy a new one.

Might also be something in your mechbox that is stuck (or hard to move because of friction), thus preventing it from moving resulting in overheat of the wires. Happened to me when I rebuilt a v2 mechbox.

Or the spring is too strong for your battery (which I would kinda doubt).

Get a hold of a reputable gun doc if a new battery does not change that. An M120 spring should be pulled by a 9.6V no problem. Ensure that the gears are properly shimmed and greased. Could also be a motor height problem, try taking a flathead screwdriver to the screw in the bottom of the grip. SLIGHT turns with only SLIGHT pull of the trigger to see if your motor height is good.

Next time you have a problem with like this, make sure to post it in the Gun Doctor section.

Not necessarily.

Get a better/bigger battery. You don't have enough power to crank that spring.

Check your battery again if it's not dead, or buy a quality battery.
Check your gears if the spin freely.
Check your anti-reversal latch.
Just because your motor works, it wouldn't have enough torque to pull back the spring.

This is a battery problem for sure, take the bottem plate off your grip and take the motor out. Hook up the connecters while your motor is outside and pull the trigger, most likely the motor will spin. You need a good quality 9.6v 2400 mah at minimum to run your operation, might as well try to run the biggest battery possible.

Good luck

I will try the 9,6 v 4400 mah that one player of my team want to sell and I will write back to say if it works.