AK47 feeding problem...

[AK47frizzle]

Ok so, you should all know I have a crappy AK that is orginally made by.... wait for it... Double Eagle.

 

Yeah that's right, Double eagle.

 

More specifically, the M900A model; the full stocked version of the M901C.

 

I only got it because it was at half price (£60) at Onlybbguns.

 

 

 

Ok, so skipping all that.... the original plastic gearbox was trashed for a full metal CYMA gearbox because I have done countless modifications to it to keep it alive.

 

But the original DE Hop Up chamber didn't... well... fit into it.

 

And what's shit about the gun is that other hop up chambers are not compatible with it. Yeah, you probs know it's a shyte gun by now.

 

So i had to compensate for it by trimming a bit of the plastic hop up chamber so that it just manages to fit in.

 

 

Feeding with .2g has been fine for a few months, still need to regularly open the gun to check on it.

 

But today, just today, I recieved my bb ammo by post (Bulldog .2g), but after cleaning the barrel and hop up chamber, I noticed that when I started firing in full auto... it lagged alot; I mean, when I fire semi auto, it's all fine, no problems. But when i switch to full auto, it misses alot of shots fired from the gearbox. Like only 2 shots are fired....

 

But sometimes, when I fire full auto, it fires everysingle shot the gearbox manages to put out.... which I find strange.

 

So, basically, it's shyte at one point but suddenly it fixes itself and reverts back to lagging again.

 

I checked on all the internals, hop up chamber and barrel. I don't see anything wrong.

 

What do you think is happening? Cause I think there is a problem with the hop up chamber itself....

[sp00n]

Have you changed anything recently? Such as a bigger battery?

[AK47frizzle]

Have you changed anything recently? Such as a bigger battery?

oh yeh, forgot to mention that! It came with a 8.4v 1150 mAh battery which was also shyte...

 

But I now use a 9.6v 1600 mAh battery and now fires around 800+ rpm .

[sp00n]

arrr try it on the smaller battery

 

if all is ok on the smaller battery, the motor may be cranking round before the piston has had chance to complete its full stroke. if this is the case, you could try lube'ing the piston , note that this is a short term measure though, but it will help find the issue.

if its still bad on the smaller battery try turning the hop off.

 

let me know the outcome of the above

[AK47frizzle]

well a 8.4v battery still isn't working. I'm just wondering the way the hop is now fitted, if the bbs don't feed fast enough....

[TPI]

Are the Feed Tube's Lining up (Could Happen!)

[Ian_Gere]

At higher rates of fire one problem that causes mis-feeds is that the tappet plate moves the air nozzle too quickly for the BB's to be allowed past it. To correct this you need a sector gear delayer, also called a tappet plate delayer. It's a little circle of POM or brass with a hole in it that fits over the peg on the sector gear and a small bite out of the circumference that the axle fits into. It does what it says - delays the tappet plate from springing back for a moment, which allows the BB's time to feed into the hop.

[AK47frizzle]

update:

 

After a 3 hour operation on my gearbox (upgrading various parts) and on my hop up (alignment), full auto is now working again! But not for prolonged periods, if i burst fire (let's say 5-8 shots), it will fire every single one. After that, it will lag on the shots slightly but still fire some.

 

I found out that my modified hop up was aligned too close to the gearbox, causing the nozzle of the gearbox to interrupt the flow of bb pellets.

 

Now the the problem has been solved slightly, the gearbox now has an extra boost of power due to the new o-ring and cylinder i put in creating an a lot better air seal than the stock cylinder and piston.