Ak Burst Problem

[strykerles]

Recently purchased an G&G RK-74-E

stock Motor seemed a bit rickety so I changed it for a 22k infinity I had spare

fired fine on semi and fine on auto

when I switched from auto back to semi it started firing in 2 round burst in both modes

any ideas??

thanks

 

[Adolf Hamster]

2 round burst on semi is normally a symptom of going too fast.

possibly it's got itself stuck on semi only now?

 

[strykerles]

i'll try another 18k motor I have and get back to you

 

[Skara]

Could also be the mosfet.

They have AB by default but they're known for busting themselves into oblivion by just existing.

 

[Adolf Hamster]

Could also be the mosfet.

They have AB by default but they're known for busting themselves into oblivion by just existing.

hmm, ab on a 22k doesn't seem like it should double fire, if anything i'd be more worried about the opposite of it locking up.

 

[strykerles]

looks like the gearbox has had an attack, it's firing a single shot then a double now

think it may have had it

trying to find a v3 gearbox is a pain too lol

 

[Adolf Hamster]

if everything's cycling fine then it's not too massive an issue.

the selector plate setup in an ak is a ridiculous rube golberg affair so it's not surprising they can have issues.

i'd pull the box apart and have a look at the cutoff lever

 

[Sitting Duck]

Bit confused here....

It "sounds" like a possible COL but gun is new-ish or recently purchased

(but then 2 round burst on auto sounds odd)

Ahhh but it is an ETU fuck pig so that would explain a burst on auto

(but that would be 3rnd or potential 5rnd burst option on ETU2 units)

Recently purchased an G&G RK-74-E

stock Motor seemed a bit rickety so I changed it for a 22k infinity I had spare

fired fine on semi and fine on auto

when I switched from auto back to semi it started firing in 2 round burst in both modes

any ideas??

thanks

Now we know the common AK selector issue going from semi/auto/semi etc...

But this TWO round burst is a bit odd - should be 3 (and/or 5 round burst) on ETU I would have thought

but still get single shot semi & then 3 (or 5 option on blue etu2) or just auto on ergh auto

First of all - what battery are you using

ETU's can/do play up on 7.4v so best to run on 9.6v or 11.1v, (11.1v is best perhaps)

(normally, iffy etu's simply refuse to work on lower 7.4v, but wondering if lower volts causing an issue)

Secondly - RTFM (Read The Fucking Manual) for info about setting/changing the burst mode

COULD be an iffy ETU - the main unit near battery, as they are made from Dairy Lea

Turn off/disable the burst mode (RTFM) and start again so semi & auto operates correctly

In that sort of gun, I would have just used 11.1v with 18k motor to get you near say 20rps

and with the 22k you should be on or just a whisker over 20rps

It appears to be crane stock AK so assume the battery goes under the hood/dust cover

which this battery MIGHT be about your limit - but YOU need to check it will fit (inc wires)

https://hobbyking.com/en_us/turnigy-nano-tech-1300mah-3s-25-50c-lipo-airsoft-pack.html?queryID=c2ca5915ed20ee36fc43e6fc49de517d&objectID=31045&indexName=hbk_live_magento_en_us_products

RTFM, check your battery is OK, and give us a bit more info...

it might be a moody selector, but the etu causes more issues in some guns than it is supposed to solve

or if gun is still in warranty contact retailer (hmm good luck with that)

but I'm a little confused with 2rnd burst in both modes so if possible read manual, turn off burst etc...

and update us with a bit more info perhaps

 

[strykerles]

The gun isn't new, was someone's backup

Came with a 11.1 1450mah lipo

Opened up the box and it looks as though it needs a clean lol

View attachment 58782

 

[strykerles]

Put back together and it fired a few times in 2 round burst and then stopped, changed battery, motor etc and nothing, dead

Etu maybe?

 

[Skara]

Etu maybe?

Most likely.

They're shit. The trigger board is fine but the fcu unit is abysmal.

 

[Sitting Duck]

Yup ETU 1 is red and the ETU unit is fucking wanked wanked wanked

Had a FFR2 A2, changed motor and it blew the ETU - WTF ???

Ripped it all out, old school trigger switch, 13:1 etc...

So me personally that is what I would do

or there is the option of Perun unit but it ain't ultra cheap....

https://www.taiwangun.com/en/wires-lasers/g-g-etu-upgrade-kit-perun?from=listing&campaign-id=19

Yeah it is very tricky to install (sarcasm) but supposed to work properly

http://perunairsoft.pl/products/gg-etu-upgrade-kit/

but me personally I'd rip it all out and go back to traditional old school trigger

coz G&G will still be a bit Dairy Lea, Perun won't leave you much change out of say £60 with shipping

and for that price, I could spend on 13:1, 25~30k motor, steel rack piston & cheap basic or diy (non burst bollox) mosfet

(you got 22k motor so forget the 25/30k motor, maybe 16:1 gears,

13:1's might be a bit too quick unless you short stroke on 11.1v

a couple of bushings under spur & maybe bevel, basic mosfet, normal switch,

steel rack piston (shs blue perhaps & cyma piston head or something that provides good seal, run on 11.1v sorted)

Well that is likely what I'd do but to each their own - but fuck G&G's ETU bollox imho

PS - looking at your pic, you might need a new COL, as it looks a bit different to reg v3 COL

(the lug that pops the reg trigger trolley looks to be set back to activate the micro switch on ETU trigger board)



see that wedge bit on right of arm, looks different to the G&G one in your ETU box

so a steel SHS COL might be needed to go old school, I noticed when I checked your pic - just saying

Before you do owt, test the board is completely dead by just having motor out of box

change fuse, but likely it is fucked

mine went a bit wanky, kept blowing fuses with motor out of box and got hot

yeah fuck that shitty unit right off I decided

 

[Skara]

I have the upgrade kit on my ARP and it's great..

Haven't really played with the settings, I have AB on and occasionally turn on binary trigger, which puts a big fat smile on my face when I'm playing cqb..

It's one of those overlooked bits that can greatly improve your gun without ripping everything apart.

 

[Sitting Duck]

I have the upgrade kit on my ARP and it's great..

Haven't really played with the settings, I have AB on and occasionally turn on binary trigger, which puts a big fat smile on my face when I'm playing cqb..

It's one of those overlooked bits that can greatly improve your gun without ripping everything apart.

Pity G&G don't use them instead of Dairy Lea ETU units, especially on their higher price guns

nice to know it works well, but wish they was cheaper, even £50 inc shipping is a bit much

I'm being a bit miffed, but mainly coz the G&G unit is so shit

(some people have been lucky and works fine still even on 7.4v, but there are a lot of issues with ETU's)

Paying a bit above other similar guns, to then have to be faced with replacing something that is so defective

spending around £50 or so, or at least a tenner converting it back to basic trigger plus time/cost is a wank

G&G - lovely looking guns, but jeez some of their ideas & innovations have made matters worse not more reliable

G&G R&D dept: ETU design & testing...

View attachment 58785

The most annoying thing is that you can't just plug a basic mosfet in

due to the 4 thin wire lead, one is power, then a signal to each of 3 switches

(power, trigger, col switch & slector switch at back of trigger unit)

so the fucking thing is only for the ETU & can't drop a basic mosfet or warfet or owt in there

so you are faced with another Dairy Lea G&G ETU mosfet, luckily the Perun option but still not cheap

or rip the whole lot out and start again old school

real PITA these fancy bespoke units - especially with G&G's reliability (ultra sarcasm)

 

[strykerles]

think i'll replace the whole unit then

thanks for all the help

do you guys know any complete replacement boxes that aint stupidly expensive?

not mega confident in my skills to work on gearboxes

 

[Sitting Duck]

think i'll replace the whole unit then

thanks for all the help

do you guys know any complete replacement boxes that aint stupidly expensive?

not mega confident in my skills to work on gearboxes

TBH you got an option to replace the ETU mosfet unit G&G £36 aprox if you can find one

or perun £50 inc ship from bravo/bullseye country sport in NI (good seller)

https://www.ebay.co.uk/itm/Perun-Airsoft-Upgrade-Mosfet-Kit-For-G-G-ETU-System-AB-LiPo-Ready-Burst-bbs/133377231128?hash=item1f0de70918:g:vv0AAOSwhQhehetA

OR contact Luke/Negative Airsoft perhaps

You could buy a V3 box, hopefully an AK with AK nozzle, trigger, selector and hope it fits OK

some v3's don't always simply slide into all other guns as is, at times a bit of modding required

(some will gladly take a std Cyma v3 & others will take a JG one but might need modding or vice versa)

those are two very common/cheap v3's out there, but there "might" be some minor fitting niggles to overcome

hence if you got a sound box that is compatible - stick with that and have it rebuilt (Luke or some other respected tech)

They can overhaul it and no doubt if old it is need of service and doubt if compression/seals are that great

Chuck in a basic mosfet, maybe the tiny perun

https://www.ebay.co.uk/itm/Perun-Micro-Airsoft-Mosfet/164224757298?epid=25036277200&hash=item263c8eee32:g:zngAAOSwP7ZdHKsv

So you can run on 11.1v, new col, trigger switch & some other bits n bobs

give it the once over and getting firing all dandy

yes labour & shipping issue, but atm you got a £300 when new gun that is wanked

so spending a bit of money WISELY is not such a bad thing

you can go nutz or Luke will advise you on the best cost effective course of action according to your budget

Or you can attempt to have a go yourself if you feel up to it, but will require some rewiring/soldering

or clean it up, slap some grease in there & buy the perun etu

those are the 3 options I would consider

(than buy a box that shoots too hot on an imported cyma v3 box & hope it fits first time)

 

[Sitting Duck]

I have the upgrade kit on my ARP and it's great..

Haven't really played with the settings, I have AB on and occasionally turn on binary trigger, which puts a big fat smile on my face when I'm playing cqb..

It's one of those overlooked bits that can greatly improve your gun without ripping everything apart.

Don't know if you tried this but wonder if it is the reset to default option

or if it is a "Whoa fuck me - what ya doing bro" warning...

But the Perun ETU plays Michael Jackson - Smooth Criminal (Eddie are you OK) if you fuck about with it...

WTF  ???

 

[Skara]

Yeah I knew about it

I guess it's just a little easter egg manufacturers put into their FCUs

 

[strykerles]

In the end I thought "f*k it" and gutted the gearbox

replaced the piston, piston head, cylinder, trigger box, tappet plate and reshimmed

changed out the mosfet for the perun version

out of the gun it seems quite snappy

i'll put it  back together and see what we get

thanks for all the help @Sitting Duck @Skara

 

[strykerles]

think I need to reshim  the box again as it got a  little grindy

also the nozzle doesn't always come back after firing on semi  and  the selector doesn't seem to lock into safe properly