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KJW M4

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@ Poopstania

Sounds like your valve is sticking - This Is The Most Common Cause of Gas Consumption - The Valve on the back of the magazine that the hammer strikes.

 

 

QUICK TEST: Empty your magazine of all gas - Once Empty Depress the Valve with your thumb and release quickly - The Valve Should Pop Out VERY Quickly & Easily!

 

If It Does Not The Valve Needs Oiling - Oil from the top of the magazine - hold the valve open with your thumb - apply 3 to 4 drops of silicon oil - watch the oil disappear into the valve - actuate the valve 2 or 3 times with your thumb -

The valve should be popping in and out quickly

 

 

Report back and tell me what you found, IF This Isn't It I'll Guide You Through The Next Steps In The Trouble Shooting.

 

 

HOLD DA PHONE!!

 

Look at the Snap Here Fellas!

 

 

KJW-GBB-M4CQB_2_mark.jpg

 

It Appears That Tanio Kobayashi Has Heard Our Bitching and ADDED A Sling Attachment!!

Edited by Raven1

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Like I said, sometimes it sticks, but usually it does not. I just did the test, and it did not stick at all. Then, on empty I did it a few times again, and it did not. This is how it usually is; only sometimes does it stick. But I always get bad gas consumption. Also, there are no leaks -- no noise, nor can I fit more gas in the mag after waiting a few minutes.

 

Ideas?

 

ETA: Awesome picture of my gun with the RVG, MI sling mount, and LaRue 10".

 

CIMG9017.jpg

Edited by poopstania

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Hi guys. I've finaly managed to crush thru the whole thread (took me almost 4 days). I have only one thing to say: I WANT THIS BABY SO BADm, that I'll probably hold on buying a new real steel handgun for a moment and get this instead !

 

And I want to give a big shout to Raven and T_Hum for such an outstanding work providing us with info and knowledge. Thx guys !

 

 

Anyway, where did I put my credit card ? ...

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@ Ruskyj

http://www.airsplat....KJW-M4-CARB.htm

 

and here if you want the shorty!

 

http://shop.ehobbyas...oba-design.html

 

 

@ Poopstania

When shooting the ten rounds, depress the valve and check if there is still gas in the magazine. If there is, then your valve either needs to be rebuilt or replaced. Next time it happens please check that and let me know if there is still gas in mag. If not then have a read below,,,,

 

Second major cause is the Plunger inside the Bolt Carrier Group - It is the Black "Plunger" in the bolt cup - You can see it from the Gas Port located on the underside of the Bolt - This is where Gas is introduced from the magazine.

If that black Plunger is Gone - then you'll have serious gas consumption. If the black plunger is damaged - to check for damage you can easily remove it with a small screw driver as it is held into the bolt cup from the Side with a capture screw. The plunger will then fall out as well as the spring. There are 4 gas ports on the plunger and they can become damaged so it is a good idea to inspect this part every 3000 BBs or when gas consumption arises and the magazines are functional.

 

If it is gone gone definitely order a spring from Clare at KJ Works plus the plunger or get the Cradle Airsoft Velocity Reducer as it is made of aluminum and will outlast your gun.

 

Please Let Me Know What you Find,,,

Edited by Raven1

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Received an email back......Um...I dont really understand. They cant send an upper reciever to the US?

 

 

1x Upper Receiver (Part 1)…we can’t sale this part to USA.

1x Bolt Cup (Part 15) ..$10 USD

2x Rubber Band (Part 26) $13 USD( for 2 pcs)

Please send me prices.

 

My address is

 

5312 Stewart Ct

Virginia Beach, VA

23464

USA

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Received an email back......Um...I dont really understand. They cant send an upper reciever to the US?

 

 

1x Upper Receiver (Part 1)…we can't sale this part to USA.

1x Bolt Cup (Part 15) ..$10 USD

2x Rubber Band (Part 26) $13 USD( for 2 pcs)

Please send me prices.

 

My address is

 

5312 Stewart Ct

Virginia Beach, VA

23464

USA

 

 

...soooo ODD!!!!!..how can't they sell a receiver????.....they sell the whole GUN!!!!!!...so we are pushed to buy a whole new gun just for receivers???......not cool man...NOT COOL AT ALL!locked.gif

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Yeah, I dont get it either. This isnt going to help me much since I need to replace that upper. Its a shame no one has come out with aftermarket bodies for the KJW yet. Hopefully this can be rectified. I emailed them back stating others have bought from them before. Sent them a pic.

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@ Poopstania

Next up to look at is the Valve Striker, The Hammer acts upon this to actuate the valve on the magazine. I had actually taken mine out of the gun and 'rounded' it off as part of some Optimizations I made for smoother performance ( I Am Capturing and Cataloging This Information for The Definitive KJW Maintenance Guide I Am Writing).

 

One Easy way to tell if the striker is partially hitting the plastic housing of the magazine - This Houses the Aluminum 'Button' that contacts the Valve Hidden and Protected Under the Upper Plastic Shell of the Magazine. You Will See Dents from the Striker Hitting on Either Side of the Aluminum 'Button.' If This IS The Case - Remove the Striker file it down round so it hits the valve in the center. You have been firing the gun for a while now so it will be to note exactly where the striker is contacting the button.

 

If this is Not The Case another area to look at is the Aluminum Button Itself. To access the button remove the 2 pins located at the Sides of the Top of the magazine. They slide out very easily so it is not necessary to 'Force' them out. Once you have them out move the Top Plastic Portion of the magazine out Evenly - If it comes out Canted or at an Angle it will not come out easily as the lever arm that acts on the bolt stop will bind on the way up and off.

 

The Aluminum Button will come off with the Upper Plastic Section of the Magazine. KJW likes to assembly these at the factory with a 'Silver Grease' named "Anti-Seize"

 

0000-Permatex-Anti-Seize-Lubricant.jpg

 

 

This grease will attract dirt and debris, as a rule of thumb if you are like I am and are not concerned to perform a Magazine change and let your magazines fall free to the ground then expect dirt, chunks of mud or small pieces of debris to collect under the Top Portion of Your Magazine!

 

What I have done is to remove the Upper Sections of my magazines and Wiped ALL of the Anti-Seize OFF. Clean everything up while the upper section is removed and note if there is debris as you are removing the upper section off the magazine.

 

Since you're in there another Optimization to do is while the Aluminum Button is OUT of the Upper Magazine Section is to file the edges of the Plastic Horse Shoe Shaped Channel - Where the Button is Exposed to the Striker Pin. Or basically the Bottom Half of where the button resides.

 

Once everything is clean assembly the magazine and report back.

 

One EASY Way to Quickly Trouble Shoot This Is To Find Some One Near You With A KJW and Have Them Use Your Magazine In Their Gun. While You Use One of Their Known GOOD Magazines In Your Gun - This Will Speed Things Up Tremendously!

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Well, there weren't any dents on the plastic, but I filed it down the groove for the valve anyway. Still no difference.

 

One thing I've noticed -- the gas coming out of the ejection port is always visible. Is it for you?

 

Anyway, I wish there were someone around here with the same rifle, but, alas, there is not. I think something valuable would be for me to order another mag ASAP.

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One thing I've noticed -- the gas coming out of the ejection port is always visible. Is it for you?

 

 

Nope, there shouldn't be any gas coming out of the ejection port, this is a tell tale sign the valve is Not Shutting as quickly as it should.

 

You may want to take that actuator valve apart and check to see if you have a cut or damaged o-ring seal.

 

And yes definitely get another magazine as soon as you are able.

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Nope, there shouldn't be any gas coming out of the ejection port, this is a tell tale sign the valve is Not Shutting as quickly as it should.

 

You may want to take that actuator valve apart and check to see if you have a cut or damaged o-ring seal.

 

And yes definitely get another magazine as soon as you are able.

 

How do I take out the actuator valve?

The brass closure has notches that look like I'm supposed to twist to unscrew it, or what?

 

EDIT: nevermind, got it out. It looks totally fine...

 

This is very confusing.

Edited by poopstania

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@ Kai_Wolf

I should have been more clear on the Gas Guns Info Post - The changes are all very slight and to be sure I did Test Fit the Older parts to the Newer Parts Regarding the Upper and Lower Receivers and they do fit! So No Issues There!

 

When Clare finally does send out a Replacement Upper to you there won't be an issue mating the Upper to what ever lower you have in your possession!

 

Apologies to @ BrooklynBorn for any confusion!

 

Here are the differences between the earlier "serialized" guns and what is rolling out now and some of these Most of you guys know about - Like the magazine spring, Stornger Action Spring for the Buffer and of course the Heavier Metal Buffer to replace the Lighter Delrin Buffer:

 

The Upper Receiver dimensions havechanged to mate to the lower receiver better,

The Lower Receiver Dimensions have been changed tomate better to the upper receiver,

The Hop Up 'Halves' (That fit on the end of theInner Barrel) have longer more open cuts, to be better actuated by the hop uparm,

New CQB Length Outer barrel,

New Added Sling Attachment where the buffer tubemates with the lower receiver,

The Piston on the Bolt Carrier Group Is 'Ribbed'and Notched to Perfect Centerline of the carrier,

There is no longer a weight in the center of thecarrier,

The buffer is now 72grams (Heavier from theprevious 60 grams),

Stronger buffer or 'Action' spring,

Stronger feed spring in the magazine,

 

 

Edited by Raven1

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@ dotty3107

Fo Sho, the parts are 100% Compatible and I purposely kept all of my 'Older / Gentle Used' parts for the purpose of test fitting to see the changes ( If - Any ) Have been made! Specifically The Upper / Lower Receivers,,,

 

 

How Ever: Please Note on the 1st Gen Hop Up Assemblies - The Brass Locking Ring that Fits over and locks together the 2 Hop Up Halves! 1st Gen Hop Up Locking Rings are Slightly L O N G E R than the Newer Brass Hop Up Rings - The Newer Brass Locking Rings ARE Slightly Shorter! Essentially the Complete Inner Barrel Assembly Will NOT Fully Seat Into The Outer Barrel - This WILL Affect Your Hop Up Consistency!

 

I found this while test fitting my 1st Gen Complete Inner Barrel Assembly into a "Newer" Carbine Length Outer Barrel - I Have No Issue In Stating That These New CQB Outer Barrels SHOULD Be Configured The Same - At Least Dimensionally.

 

I Mention This Only Because Some of Us May Purchase the New CQB Barrel ( I Know I Will ) once it becomes available.

- If this IS the case,

- AND You Have An Early Model IE: Serialized Gun - Then the Brass Locking Ring Will Need To Be Filed Down Slightly So The Entire / Complete Inner Barrel Assembly Will Fit and Seat Fully Into The "Newer" Outer Barrels!

 

If you have a newer model gun then you are GTG!

Edited by Raven1

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@Raven1

Thank you for the info. I have no plans converting my MJW into CQB, jet. In my opinion, you should apply for a job in KJW as external consultant and/or customer support :)

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Ha!

 

Seriously Tho - I first got into the GBBR world with an AGM M4. Spent $1,200 USD on it and I NEVER Fired a Complete magazine through it with out something breaking!

 

Frustrated as hell a buddy of Mine you guys might know as "Snoopy" turned me onto this gun! So once Snoop - A - Loop started talking up this gun I had to check into it.

 

Well as you ( Or most of you ) have read I complete Beat The Sheot Out of My Gun! I PURPOSELY Tried to make the gun fail and break and even when it did it still Fawking Ran!

 

 

So here I be preaching the Gospel of KJW, it is a great gun that works out of the box Running Propane!

 

So Anyone Can Go Out - Get Their Air Ball On and Still Have Money In Your Pocket.

 

 

Look Brohs I'm Really Just Trying To Help Out - The Economy Sucks - Money Is Tight - All I'm Saying is "Look! Here's a great gun that you Don't Need to keep throwing money at!"

 

 

You know the KJW M4 is like the Chubby Girl you started dating over the summer because you knew NOBODY Would find out you're banging a Filthy Pig. But Then HOLD DA Phone come the Fall Season your chick went from Ugly Betty to Scarlett Johansen in Iron Man 2! SCORE!!!

 

I'm Just Sayin,,,

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Because of your posts I've decided to buy this gun and I have no regrets. It's absolutely great! So, I thing we're all can be very happy to have you. Keep goin'....

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Raven1, since you are in contact with the VFC guys doing the GBB.... have you tried selling them the Koba system?

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