WTF? TM-hi-capa 4.3 firing Full auto only, Hammer won't stay cocked -- VIDEO
 

No idea whats going here, I think it might be my trigger sear. When i pull back the trigger, or cock the gun, the hammer does not stay back, it simply falls forwards. This means when the gun cycles, instead of the hammer staying back at the end of the cycle, it simply falls forwards again, making it fire full-auto


When i try it with a filled mag, it empties the mag full-auto.

This would be cool if it was controllable, but its not, i don't even have to pull the trigger for it to fire.

Any idea whats wrong? Gun is maybe 12-18 months old, sees regular play.

Thanks,


Funny, I was just looking into modding my BBU for full auto :\

VIDEO: sorry if the quality sucks, filled it on my phone

YouTube- airsoft.3GP

sounds like the sear has worn down, as well as the spring in the hammer may have broken, worn out stretched etc....
and it is a year old with stock parts after how many rounds?

airsoftparts.ca my friend time to get replacements

Probably 2Kish rounds, cleaned and lubed semi-frequently.

I just shot a quick video to show whats going on, uploading it now.

Added a video to the original post

take off the pin in the grip, remove the hammer spring housing and checkout the spring (then replace if fine), then take out the leaf spring from the grip and have a look, then compare it to what a new one looks like, then replace it back in the gun and make sure it's in its proper place and test fire again

Will do, thanks.

oh and don't lose the little nub that keeps the spring and plunger in the hammer spring housing.

Did you disassemble your gun recently? In particular, did you access the leaf spring?

Your trigger disconnect lever isn't functioning properly.

http://www.airsoftcanada.com/showthread.php?t=94413


See Post #4 - Troubleshooting.

Q2/A2.

There's a photo there that shows how the leaf spring SHOULD be seated.

Okay, I'm new to GBB internals, so bare with me here.

I disassembled it to hammer/trigger assembly.

Is this assembled correctly? I am checking all of the parts of wear, but I don't see anything that looks especially worn.

http://i518.photobucket.com/albums/u...g?t=1264717605

http://i518.photobucket.com/albums/u...g?t=1264717645

That more or less looks okay... the trigger disconnect lever (the silver part) should be more vertical. IE, the bottom point should be facing towards the 6:00 position, rather than at the 5:00 position it's pointing to now.

The part that sticks out at a right angle (towards your face) should actually sit to the LEFT of the sear. So when you picture the trigger stirrup in place, the stirrup will contact the silver part, which will in turn push the sear to release the hammer.

See my post right above yours.

Alright, Thanks ILLusion, ill double check that now,

How did it turn out?

Sorry about taking so long to get back to this,
Last night was my friends birthday, so I didn't really have enough time to take a good look at this.

I have today off though, So I will update shortly.

Thanks again for all you help Brian.

Alright, Its back together, and appears to be functioning correctly.

All this GBB internal fun has sparked an interest in some serious upgrades! :D

Thanks again ILLusion!

What was the problem? Was it as I'd stated?

I belive so, Although I don't really know enough about GBB internals to accurately diagnose what was causing the malfunction, when I re-seated the leaf spring and adjusted the trigger disconnect lever, It seemed to work fine.

Sorry if thats not very descriptive, I frankly have no idea what I'm talking about :)

I know the problem is fixed, but I still have one question. Is that how the disconnector lever naturally sits? When I took apart my stock MEU that's what it looked like on the inside.

No... the hook at the bottom (that juts out 90 degrees towards you if you're looking at it as the above pictures) should be just below or behind the sear, depending on the cycle state.

This piece is the sear disconnect lever. When the hammer is cocked and the slide is in its closed state, this lever will be sitting behind the sear, between the trigger stirrup and the sear. When the trigger is pressed, the stirrup pushes the lever, which in turn, pushes the sear. Once the sear reaches the exit point of the hammer hooks, the hammer breaks, and the shot cycle ensues.

The sear disconnect lever will remain behind the sear for the entire duration of the shot, but the moment the slide begins to move, the blowback unit's legs will depress this sear disconnect lever, and the result is that it drops down below the sear, which allows the sear to pull back and return to a state which hit can engage the hammer hooks to cock the hammer again.

When the slide returns to battery, the trigger disconnect lever is allowed room to rise again, but until your finger releases the trigger, the trigger stirrup is blocking the disconnect lever to rise up behind the sear. Once you release your finger, the trigger stirrup allows enough room for the trigger disconnect lever to rise up behind the sear again, and the cycle is reset, pistol ready to fire again.

That's kinda freaking cool.

In a quick "OMG" situation, draw our your pistol flip the hammer hoze and hope for the best!
Hahaha. Great for humor.