[Insert Bad Words Here] M4!

[Liam Porter]

Having serious problems with my M4 AEG, making it unusable. I'll start from the beginning. Sorry for the long read.

 

I have an A&K M4 it came from XSite and was a Christmas present my step-dad got me, so is a good ¾ of a year old. The warranty has run out as it had a 6 month with it.

 

It's recently been re-wired to the front handguard (from rear crane stock), which I discovered it has no fuse in it.. need to get one me thinks..

 

Internally, it's completely stock and externally it has a few new parts, which are great and don't effect what I'm asking.

 

Took it to Urban Assault at RAF Upwood today, and instead of my day being ruined by the regular cheats, my gun did it instead.

 

Went to chrono it, the hop-up on minimum possible, BBs still fly way too high and is not even usable. So I use my step-dad's G&G for the first half of the day.

 

At lunch, I took my M4 apart to sort the hop-up out, no matter what I did, it stayed the same. Made sure the rubber wasn't folded or anything, made sure the nub was in correctly, tightened the gears. Still no difference, these are all stock parts.

I had a spare MadBull red rubber & nub, tried to fit those, the rubber seemed too long and the nub was also too long to fit, so I saved those for my sniper.

I now have a small piece of pen ink tube as a nub, which is slightly smaller, but harder, than the stock nub, and solved the BBs going too high problem.

 

And then I get a new problem, set the hop up perfectly. Shoot, after a few shots, the hop-up is turned down by the force of the BBs, so it's now held in place by tape.

 

Hop-up was then okay (ish) for the rest the afternoon, but impossible to adjust.

 

Another problem I ran into, which I have before with this gun, but not as bad, was the batteries.

I prefer semi, as I like my BBs too much to was them, which means pulling the trigger on and off a lot. As semi is dodgy (more below), I kept it on auto but only tapped the trigger, occasionally using bursts when people didn't take hits. Randomly, but very frequently, the gun would suddenly stop working, as if there's no battery in it. So I swap batteries, 10-15 minutes later, same thing happens. I put the first battery (presumed dead) back in, and it shoots perfectly fine again - for 10-15 minutes, then I have to swap the batteries again.

The batteries are not overheating, not even warm, I've tried a total of 7 different batteries today, all of which were perfectly fine in other guns, but my gun still did the same.

I have no idea what is causing this, could it be the motor? Gear box? Lack of fuse? Help please!?

 

And about the dodgy semi, when on semi, if I shoot fast, the trigger will lock as it it's on safe, to get out of this, I have to switch to full auto, shoot once or twice and then it'll be fine again. Any ideas what's causing it?

 

If I need any new parts, please suggest which ones (with links) that are good but affordable.

 

 

I'm sticking to sniping from now on - may cost more, but at least I don't have all these problems..

 

Thanks a lot, and even more if it fixes it!

[M_P]

Trigger contacts maybe..... but I'd wait for someone who knows more than me to reply

[TPI]

The semi sticking is just where it still needs wearing inand the others im stumped

[Liam Porter]

What you mean wearing in? I've had it 8 months and it's only started happening recently (before taking apart and re-wiring).

 

Thinking about it, they've all started before taking apart & re-wiring actually, apart from the hop-up. That's just today.

[TPI]

Yea but have you fired it alot it not like leave i and it will come back but you have to us it alot like 100.000 bb's through it alot

[Liam Porter]

What does that have to do with the trigger? It worked perfectly fine for 6 months or so, then messed up once the guarantee ran out.

 

You may be thinking of the hop rubber if I need 1000s of BBs through it to wear it in, but it's had enough through it and has been working fine previously.

 

 

I'm going to blame my sniper - it got jealous because I didn't take it, so it messed this gun up.

[M_P]

i still reckon the trigger contacts are dirty from carbon build up, but im no whiz on internals, i only know basic stuff

[Liam Porter]

I shall take it apart and have a look tomorrow, as got a BBQ to attend now

[TPI]

Well i am just as stumped then could be the contacts as marksman has said

[Airsoft-Ed]

Almost every AEG I've known has had the semi fire locking problem, my brother has an Ares L85 and my mate has an A&K AKS 74 and had an A&K AKS 74u it happens to both of them all the time.

I think it's just one of those niggles you have to live with.

They both have been doing.

 

Perhaps it's more prevalent in A&K AEGs.

 

The L85 has the same hop issue as well and I agree it's annoying as fu... Well, yeah.

 

The hop adjustment is a wheel type with the Ares so I was thinking of just tightening the screw that holds the wheel in, see if that might help but I've not looked into it yet.

 

The breaking thing with the battery also happens to my mate's A&K AK and every time it does he just has to reset the motor/gear box. There's a switch inside it or something, then it's fine again for a while.

 

He had to do it 3 times over a 7 hour day last time we took it skirmishing.

He also had to disable to blowback so that might be something you could try if it's applicable to your M4.

[Liam Porter]

Thanks, I know what the semi problem is now. It's when you tap the trigger fast, if it's too fast, then the piston isn't pulled all the way back, so no shot is fired, it just sits there, but the thingy that prevents semi working same as full auto thinks it has shot, so it locks it to prevent further firing. If that makes any sense.. Anyway, to solve I'd need a faster motor and faster response from the trigger.

 

The little screw just holds it in place, it doesn't make it harder or easier to adjust, so it's not that.

 

Mine will work without taking apart or anything, just you have to use a different battery.. until it does it again.

 

And mine's non-blow back, so that's not effecting anything.

 

Think I need to buy replacements for all the internal parts, or just a new gun..

[bigshep]

faster trigger response, use a 9.6v battery or fit a mosfet

 

hop unit, replace it with another hop unit, they cost around £20 or so

http://www.actionhobbies.co.uk/Ares-M4-M16...er_AYYQ2.aspx?0

http://shop.ehobbyasia.com/king-arms-m4-me...er-for-aeg.html

http://shop.ehobbyasia.com/gandp-m16-metal...6a2-series.html

 

or use a small spring washer to keep the hop tensioned

http://www.mechbox.com/m4m16/m4-hopup-fix.html

[Cerbo Knight]

If you fit an AB mosfet, you'll get a complete cycle everytime no matter how lightly you tap the trigger

[Liam Porter]

Okay, so that's two problems with solutions then.

 

Any idea about why batteries die so quickly? I've checked to see if it's shorting out at all and can't see that it would be. Any ideas?

[Cerbo Knight]

I'm thinking that your gun has a loose connection somewhere, so it appears that the battery stops working but in reality the circuit is just broken. It's most likely the battery connector is loose, that would explain why when you put a new battery in it works (maybe it shakes it into connecting?)

 

Just a thought. Though I'm willing to bet it's something to do with your wiring and it's fairly simple to fix.

[Liam Porter]

That is a good possibility. Especially considering that my step-dad re-wired the gun and batteries to different size Tamiya. I'll check them and see if I can solve the problem.

 

Has anyone used the MadBull G36 style hop unit for the M4? I was thinking it would probably hold its position better than the standard M4 one.

[Cerbo Knight]

The madbull ultimate unit? Overhyped IMO, just sand a bit off of the top of the main wheel's post, it lets you tighten the screw more so it won't move

[Liam Porter]

Yeah that one. I won't get it then, will get normal style. Any recommendations on brand? And what hop rubber and nub (my nub disappeared last time I took the gun apart, somehow!)?

[Cerbo Knight]

I used to use a G&P unit in my old JG M4, that worked pretty well.

I've heard that the Prometheus neo strike chamber is pretty good too.

 

I'd either go with a TM rubber or a guarder clear if you're not going for a specific role, they're the middle ground between durability and performance IMO. Good for me and good for you

[Liam Porter]

Okay, I now have a to-do and a to-buy list for my M4. Time to start doing & spending.

[Cerbo Knight]

Forgot to add the nub, I'd go for a H-nub or an SCS.

 

Let us know how it turns out

[Liam Porter]

Okay, one last question. How much are mosfets (link please), how do they work and how do I install them?

[Cerbo Knight]

Depends on what mosfet you go for, some are cheap (I saw 2 AB ones on zero in for £25 and £35) and some can go up to £70 or so.

 

I make my own, because I can.

 

 

There are two types of mosfets. Mosfets that drop in (Like this one!) and plug in before you battery does, and mosfets that need to be installed and the gun needs to be rewired, and it's a lot of work for someone who doesn't know what they're doing.

 

The plug in mosfets are easy, and provide basic burst fire and I think one of them helps trigger contacts (delays the flow of current until the trigger contacts are together this stops the arcing you often get) but on the whole most don't do this. The mosfets you install always protect trigger contacts due to the way that they're wired in, and some have burst features (the ones I make dont, because I don't generally need/want a burst fire).

 

IIRC, you should expect an increase of rate of fire by about 20% with all mosfets, or that might be with just the installed ones... I can't remember.

[Liam Porter]

Wow. That is so simple, even more simple than leaving your phone on a bus.

I'll have to get myself one if they're so cheap, it may solve the battery issue too as it's different contacts and helps the trigger contacts.

 

How do you make them?

[Cerbo Knight]

using science

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

and school supplies