Feed Problems

[Lockdown_Neil]

Hi, So I was given an SRC M4, I realised the tip of the air nozzle was broken so did my best to measure the length and ordered an alloy replacement.

It now miss fires a fair amount and even more so on full auto.

I'm guessing this is due to the nozzle being too long? Any help would be appreciated 

[Lozart]

13 hours ago, Lockdown_Neil said:

Hi, So I was given an SRC M4, I realised the tip of the air nozzle was broken so did my best to measure the length and ordered an alloy replacement.

It now miss fires a fair amount and even more so on full auto.

I'm guessing this is due to the nozzle being too long? Any help would be appreciated 

 

Couple of questions - did you change anything else and when you say "misfire" I assume you mean no BB rather than more than one BB at a time?

 

If the nozzle is too long then yes, you would have feeding issues.

[Lockdown_Neil]

2 hours ago, Lozart said:

 

Couple of questions - did you change anything else and when you say "misfire" I assume you mean no BB rather than more than one BB at a time?

 

If the nozzle is too long then yes, you would have feeding issues.

I changed the cylinder as well and the hop rubber

Yes I mean no BB so every 5 shots maybe 3 come out but definitely not double feeding. 

 

[Piman]

A hop rubber that is slightly too long can also cause this. Can you see the lips of the hop rubber through the bb feed tube? Generally you will be able to see them but only just. (<1mm). Th bb drop test can show iff bbs are getting caught (i.e. with the hop and barrel out of the gun drop a bb into the infeed tube and it should drop straight out the back without any resistance.

 

Otherwise it might be a nozzle length issue as suspected. When you say you measured the nozzle what length did you measure and what length did you buy to replace it? Did you notice if there was a delay chip on the gear when you replaced the nozzle. 

[Lozart]

1 hour ago, Lockdown_Neil said:

I changed the cylinder as well and the hop rubber

Yes I mean no BB so every 5 shots maybe 3 come out but definitely not double feeding. 

 

 

Cylinder shouldn't cause poor feeding unless you've done it REALLY wrong!

 

As @Piman said though a hop rubber could cause an issue. If your nozzle is too long as well then absolutely!

[Cr0-Magnon]

Sorry to hijack the thread but my 100% stock Specna Arms SA-E01 Edge 2.0, which I tried to skirmish for the first time at the weekend jams pretty much every shot. I'm even using the mid-caps which came with it. One of the few things I can do to an AEG is install a new hop unit, rubber and barrel so I swapped over the stock unit for a ZCI I had lying around and it's still happening. Could it be something inside the gearbox? If so, I'll just take it to a local tech.

[Piman]

There are a lot of factors - Nozzle length, nozzle alignment, nozzle timing (tappet plate + spring + gear with or without delay chip), Hop alignment (to gear box and magazine), hop rubber size, magazine performance (alignment in receiver, spring strength, BB retention clip).

Those are what I can think of right now and some will be far more significant than others.

 

Has the RIF always done that from new and how old is it? Is there an option for a warranty inspection?

[Lockdown_Neil]

2 hours ago, Piman said:

A hop rubber that is slightly too long can also cause this. Can you see the lips of the hop rubber through the bb feed tube? Generally you will be able to see them but only just. (<1mm). Th bb drop test can show iff bbs are getting caught (i.e. with the hop and barrel out of the gun drop a bb into the infeed tube and it should drop straight out the back without any resistance.

 

Otherwise it might be a nozzle length issue as suspected. When you say you measured the nozzle what length did you measure and what length did you buy to replace it? Did you notice if there was a delay chip on the gear when you replaced the nozzle. 

 

Hop rubber seems ok when tested as you described.

 

The old plastic air nozzle was fairly beaten up so I had to try and reconstruct it, best I could see it came out at 20.53mm with my digital caliper, I went for a 20.5mm replacement so if anything slightly shorter.

 

There wasn't a delay installed but that might be a good shout, I'll try a new tappet plate first as I have one somewhere.

 

Thanks for the help guys, I'll let you know how I get on.