KWA M4 Trigger Lockup *Resolved*

[Maalkus]

Hello all,
I've tried searching for a solution to my problem, but I can't seem to find anything to help me.

A friend of mine recently got a KWA M4A1. After a few test shots it felt as though the nozzle wasn't moving properly. After taking apart the gearbox, we got the nozzle moving but a new problem arose. After reassembling the gearbox, I found that the trigger would not pull back in Semi-auto (It would pull back in full-auto). After some more fiddling with the gearbox, we eventually got the trigger to pull back (in semi-auto) but it would lock back and not return on its own. I am thinking that this may be a problem with the gear timing. If anybody has some information it would be greatly appreciated. Thanks in advance.

Edit: So I just had a touch of idiocy. I found the problem. The spring that sits underneath the trigger had fallen out I didn't notice. Thanks to everyone for their speedy responses and great info.

[m102404]

There's no such thing as gear timing.

Problems with trigger movement in a version 2 mechbox come from either:
1. The trigger spring

or

2. The safety arm

1. Trigger spring
- there's a hole in the trigger that the short arm needs to fit into...if it's not in there you may not get a closed circuit when the trigger is pulled
- the long arm needs to be in the mechbox...sounds obvious, but sometimes when you're putting the mechbox back together, it'll slip out and be on the outside...obviously then it won't work
- the trigger spring is the only thing that causes the trigger to reset when you let go of it....if it's not returning back, either the spring is installed incorrectly or the mechbox is binding the sides of the triggers (probably not your case because that trigger did work in that mechbox before)

2. Safety Arm
- the arm that swings up to physically block the trigger is controlled by the movement of the selector plate on the left side of the mechbox.
- when up, the arm should physically block the trigger from moving...on some switch assemblies...this is the only thing that prevents the circuit from closing.
- when in semi or full...the arm should be swung down enough so that the trigger can be pulled enough to complete the circuit.
- with mis-matched parts (selector, safety lever & arm, trigger, selector disk, body, mechbox) a situation can arise where when the selector is moved to semi...the safety arm hasn't moved enough down out of the way and is still blocking the trigger. you can easily check this by moving the selector a bit more, and more until it shoots semi.

Since this mechbox worked before...and assuming that you haven't randomly swapped in different parts....and assuming you haven't broken anything...my bet would be that you've got the trigger spring installed incorrectly.

Best of luck!

Tys

[LyquidFyre]

Trigger return is determined by the trigger spring. Not sure how gear timing would affect the ability of the trigger to return to it's ready position. Check the orientation of how you re-installed the trigger and the spring.

Or see post above.

[Maalkus]

Thanks guys. I'll check on both the trigger spring and safety arm and report back.
Just a note: the AEG is pure stock, no modifications. Also, as I pull the trigger back in semi-auto mode I can hear a faint click as it reaches the back. Once it locks, the trigger needs to physically be moved forward again.

[SHÖCK]

I think I heard of this same thing happening to a friend's KWA. KWA's trigger is different from other V2s IIRC.