Black Ops M4 Cobra Locked Up - HELP!!

[Buzzsaw]

I have an Ignite Airsoft "Black Ops" Cobra CQB M4 that just locked up and will not fire. When you pull the trigger, you can feel the motor try to turn, but there is just a slight bump and a audible clicking sound. I'm not sure if it helps, but the underside of the lower receiver is stamped 2012 Bear River International LLC Item# 3500 (just above the trigger guard).

The weapon was functioning fine and then just stopped without warning. When you pull the charging handle, it simply falls all the way back with absolutely no resistance. I tried simple stuff like cycling the battery, and checking the mag/barrel for obstructions and found nothing odd. From watching one of your videos, I was able to remove the upper receiver to have access to what I assume is the gearbox. In the gearbox, there is an orange piston, that I'm guessing is the key to projecting ammo, which appears to take up almost the entire length of the mechanism. That piston appears to be stuck in the back position with the big spring compressed. I compared this weapon to my working Black Ops M4 Viper, and the Viper's piston is all the way toward the front of the gearbox.

I tried gently pushing the stuck Cobra piston forward but it didn't budge. Since the tolerances are so tight I didn't want to put too much pressure on it. Has anyone ever seen this problem before? Any suggestions on how I might resolve the issue and prevent it from happening again? I've never been inside one of these guns before, so this is the farthest I've been in the disassembly process. If you have suggestions, I would appreciate detailed instructions on the steps to take, or if you could possibly point me to a repair manual somewhere?

Thank you in advance for taking the time to look at this issue and offer your suggestions.

[Dominum]

The easiest way for you to fix this, since I presume it is just locked up, is to pull the piston backwards as you pull the trigger. You'll need to use your fingers so you don't damage the piston, and you'll need to hold it very firmly and pull back hard.

[ibeezthecapn]

i would say post a photo.

[Dominum]

Now that I'm off work, you can just call me and I will walk you through it. 803-609-7681.

[Buzzsaw]

Okay Capn, I've got a couple photos of the issue. How do I insert the pic's in my post? I tried using the Img tag, but it only appears to work for URLs. Is there a way to add photos directly from my hard drive?

[Buzzsaw]

Dominum, I tried to reach you but no answer. I've also sent you a PM but it appears to be sitting in my Outbox and not actually being sent. Yesterday was my first day on the Forum. Is there something else I have to do to get my PMs to send?

[Romba]

You cannot insert them directly from your computer, you have to upload them to imagur or photo bucket and use the IMG code.

PMs sit in your outbox until the person views it. Dom is probably at the pool party right now, so that's probably why he hasn't seen it or responded to your phone call.

[Dominum]

^I was at the party all day. I'll call you after I get off today.

[ibeezthecapn]

fixed


also look for the "how to properly shim an AEG" link on here (i believe it is on Star_Folder's signature) for tips on safely opening a gearbo, and take a few pic of the inside. most likely you will see whatever the problem is as soon as you open it.

[Buzzsaw]

Sorry Romba, but that obviously didn't work the way I thought it would. Here are the photos I was trying to post previously. Sorry for the confusion. As you can see, the piston is stuck in the back position with the spring completely compressed. Any ideas?

[Buzzsaw]

[img][/img]

[Buzzsaw]

Dom, thanks again for taking the time to talk me through this issue. I REALLY appreciate you spending so much time on the phone today educating me on the various mechanisms in this gun. I have already ordered the Dean connectors, and will go tomorrow to get a Lithium Polymer battery. The RC shop near me stocks both the Voltz and Traxxas brand LiPo batteries. Have you had any experience with either of these to be able to suggest one over the other?

[Dominum]

No, but as a general rule nowadays even cheap LiPos are fine for airsoft, since they don't draw large amounts of electricity for extended periods of time like RC cars and planes.

It's np, now that you have my number you can txt or call and I'll help as best I can. I enjoyed talking to you and I hope you make it out to SC to play sometime!

[Buzzsaw]

Okay, I got the Cobra back together. The good news is that I ended up with exactly the correct amount of each part, screw and connector. No spare parts is always a good feeling when putting one back together. Unfortunately, after getting it back together, I gave it a quick test and it did the exact same thing so I had to take it completely apart again to release the anti-reversal lock. After rebuilding the gun a second time, I was nervous to test it again so I used a different battery. This time I used a battery with the exact same spec's, but one that was new and had never been used before. This time the gun cycled successfully on Semi a few times, and on Auto as well. In my mind, this just goes to prove your thinking on the power supply system. The old battery obviously has enough juice to trigger the MOSFET, but insufficient current to completely cycle the motor. I'm out today to look at LiPo replacements Thanks again for the help and knowledge.

Here is the reassembled gun.

[Dominum]

Yep, that's what I meant about those cheap little 8.4s that come with guns.