New G & G t4-18 firing problem (after rain?)

[Redneck]

Thanks for your previous advice on upgrading my new gun (top tech t4-18) however things seem to have gone a bit tits up. I played this Sunday in the rain. Didn't have any problems until the last game at the end of the day. She started firing 3 round bursts on semi and sticking when fired in auto. The guys at the sight gave me advice about it might be, but before I contact the shop (it's less than a month old) has anyone any ideas/simple solutions/ similar experiences? I've tried removing the front rail and stock and letting it dry but no joy........

 

[Zak Da Mack]

personally, I would just give to the store and let it be repaired under warranty if you have that. Better than to try and sort it out yourself and void the warranty in doing so.

 

[Shizbazki]

To OP

Hi,

I read your original post about your G&G TR4-18 which you got from Land Warrior Airsoft (LWA) about upping the spring strength so you could shoot closer to 350FPS and now you are having problems with apparent water ingress.

SO i am here to help as I:

1: Tech my own guns

2: Also own a G&G TR4-18

3: Also got mine from LWA

Now obviously the TR4-18 comes in two lengths (TR4-18 standard and TR4-18 Light (shorter barrel)) and colours of black and tan, mine is the TR4-18 Light in tan, when i got it from LWA i got it with the dark earth 10.5" Geissel Rail which i had to fit myself and found it shooting about 375FPS using ASG Blaster 0.20g BBs (way too hot) so i had to open it to reduce that so my TR4-18 shoots a very consistent 340FPS.

To upgrade the spring i would recommend you purchase a M110 Spring from a good company such as Guarder, then follow any of the Youtube videos to disassemble it and get to the gearbox, now an M110 spring will up the FPS but this would push the gun over 350FPS so you may need to use some wire cutters and clip about 3 or 4 coils from the spring (piston side) to lower the FPS which is what i did on my TR4-18.

Remember that your TR4-18 comes with that pneumatic blowback, unusually the more hop you apply the higher your FPS (normally its more hop equals less FPS) and this is because of that blow back system as i think G&G install a stronger spring maybe something like an M105 to compensate for the blow back system.

As for the triple shot thing you state that on semi its doing a three round burst as in three cycles of the gearbox and a shot coming out with each cycle and that on full auto its sticking, i'll take the sticking to mean the gearbox is locking up? Stupid question but were you using the same battery all day? As the locking up would indicate a nearly empty battery, but still it would not do a 3 round burst.

First thing ill ask, during or after the game was there any water ingress into the buffer tube? I ask this because that is where G&G installed their so called 3rd Gen MOSFET (read piece of crap that gets super hot and blows when using 11.1v LiPos and you should get rid of ASAP) and that your issues could simply extend from that being shorted as its usual heatshrink (bot very well either) to insulate it from the tube.

It the MOSFET looks fine (should still replace it) then your second check (without voiding warranty) would be to open the bottom of the pistol grip (taking care NOT to strip the screw heads), remove the motor (again taking care not to damage the motor contacts), then remove the pistol grip (two screws inside the grip again taking care not to strip the heads) and then looking inside the bottom of the gearbox with a torch. Check and see if the Anti reversal latch is correctly aligned (see Google), that there appears to be no wear on the gears or piston (might be hard to see), i would also pop the ARL using the spring decompression button (right side of the upper receiver just in front of the cocking handle), see if every spins fine then using a small screwdriver spin the bevel gear as far as you can watching if the ARL is latching properly on the Bevel gear.

If everything appears fine then reassemble it, power it up and shoot it a few times, if its still doing the same then you are going to have to open the gearbox and void the warranty, its only then you might be able to spot what's wrong with it such as a stripped gear (has never happened to me using stock G&G gears in my TR4-18, M14 EBR and MP5). Sometimes there is nothing wrong and for some reason the gun is just playing silly buggers, my MP5 would not shoot when powered even when everything appeared ok in the gearbox, it was only taking it apart (on a skirmish site too, talk about field teching) and putting it back together that something must have just fallen into place and worked.

Whitlst you have the gearbox open you may as well as swap out the old mosfet for a new one, i would recommend a GATE Electronics PICO AAB as its about the same size as the G&G one and all you will have to do is splice it on to the G&G wires which are actually very good.

FAILING that if you are not confident in opening and putting the gear box back together send it to the shop, i would ask that they up the FPS to 350FPS and fix that 3 round burst thing.

I hope this helps you in anyway, any questions feel free to post here and ill try and get back to you.

 

[Redneck]

Hi Shiz, I've just seen your post tonight. First of all can I say thanks so much for taking the time to write such a detailed and informative post. I actually sent her back to LWA to fix the problem and to do the spring upgrade at the same time. They have had it nearly 2 weeks. I did email them last week to ask about progress and they said they had been busy but the work would be done sometime last week. I still haven't heard anything......

Anyway, back to the other issues, when I said sticking on full auto, I mean it didn't stop firing when I released the trigger , not the gearbox locking. I didn't notice any water in the stock but it's possible there was.......I've read a few things about the gen 3 mostest being shat and burning out even totally dry! The battery's where totally fine. I always swap at lunch and so it had barely been used.....I even tried it with a fresh battery when I got home just to check but with. The same problem.

I think I do need to change the mosfet by the sounds of it, and everything else you said sounds like the sensible way to check but it does sound terribly daunting to me as I've only been playing a few months and have virtually zero knowledge and experience of dismantling a gun. Don't want to learn the hard way on a £320 rifle. I guess I'm going to have to learn if it's going to take weeks for lwa to sort it out!

Cheers for your help

 

[Shizbazki]

When I said sticking on full auto, I mean it didn't stop firing when I released the trigger

Ah this makes much more sense now and makes me wonder why LWA has taken ages to sort it out for your gun seeing how its actually an easy fix, it might be because they have a back log or something.

Picture shows the offending piece: View attachment 15606

In the picture you will see essentially what is the trigger contacts from another AEG using the version 2 gearbox, as you can see just above it is a spring on one of the trigger contacts and sprung over a post just to the left of it.

What simply has happened is that this spring has fallen off the trigger contact or the post so is no longer pulling back the trigger contacts apart.

When in full auto you pull the trigger, that pushes the contacts forward causing the gun to fire, normally by letting go the spring pulls the contacts apart but because it it no longer under tension its not doing that. When in Semi auto, you pull the trigger causing the shot to fire, normally theres a small cam on the sector gear which hits a small latch (on the left of the picture held down by the black screw) that flicks the contacts apart and the spring does the rest of the work to pull it back, however when theres no tension the contacts are closed causing it to fire, after a few shots the latch pulls the contacts apart enough to stop the shooting hence the burst fire you're getting.

Glad to be of help, give LWA a call and see what's happening regarding your gun.