Tech Help - APS AK74U Fire Selector

Hey all, asking for help with my APS AK74u.

Selector switch wasn’t right when I bought it secondhand. Have pulled gearbox out and tested that it does in fact work both semi and full auto.

Problem is that I think the selector can switch the gearbox to semi, but full auto requires me to push the selector on the left hand side of gearbox past what the selector on receiver side can do (as pictured). I feel that I have the selector teeth correctly meshed for full travel. Any help troubleshooting is appreciated :+1:
image
image
image

1 Like

Trying to attach photos but says I can’t embed media in a post :man_shrugging:

I’ve got an AK V3 gearbox on my bench at the moment (at home) so I’ll get some pics tonight for you regarding the correct orientation of the selector.

2 Likes

Right, I’ve read over the question again and I’m really hoping that what I’ve got can help, however there’s something you said that has me a little confused.
You stated that:

I’m going to some pics, they might shine some light on this.


The yellow arrows indicate positions that need to be noted


Selector plate full travel to the left


The line indicates the orientation of the fire select lever on the receiver


Note that the notch that allows the cut off lever to engage is right at the end of the selector plate

Ignore the fact that there are no contacts on the selector plate; this V3 has a different method of completing the circuit (a topic I’m going to share elsewhere).

I didn’t get any pics of the ‘full-auto’ position because it lies in between safe and semi. Which brings me to your statement above.

“…past what the selector on the receiver side can do”.

All the way down is not full auto, it’s semi. Full auto is when both contacts are covered by the selector plate but the cut off lever is up.
That notch in fig. 4 is positioned right at the end so the semi function is located at the end of the travel of the fire select lever.

Here’s some pics of a selector plate that does ‘safe, semi-auto, full-auto’.


A: circuit completed
B: cut off lever notch still engaged


Cut off lever pressed up by selector plate at full travel, disengaged

I apologise if this doesn’t help as I may have misinterpreted your question/statement. I may have confused you even more. At the very least it gives a visual representation of what the armatures look like in their proper position. Again, I know these aren’t APS gearboxes but the principle should be the same.

Sorry, I’ve had a cunt of a day :unamused:

6 Likes

How come you can post pics?! :sweat_smile: thank you so very much for your write up! It’s very appreciated. I’m going to sit down and look at my gearbox again tomorrow morning, compare with your notes. If you’d be willing, maybe @moderator1 can open a DM between us two?

Thank you again so much for helping me out :ok_hand:

1 Like

The information in this thread is far more valuable to others.

That is an outstanding image list and description of how the fire mode assy works too @Farmercyst

4 Likes

Well fucking done ! Such beautiful crisp clear photos and explanations :+1:

4 Likes

Let’s keep this information public, far more useful and everyone benifits :+1:

1 Like

Is this active engagement in bending of Forum rules? Would you like your embedding/linking privileges also taken away?

Oh um, sorry. Deleted :>

So how come he was able to put photos in and I can’t? I have similar photos to him showing my gearbox, would help get my point across

@Farmercyst has earned said privileges by being an upstanding and helpful member of the Forum. You should aspire to be like him.

3 Likes

Aw, okay. I figured it would help me illustrate my issue better, not just spamming memes or anything unproductive :confused:

Thanks everyone, tbh I wasn’t quite sure if I was addressing Eriks issue or making it worse.

They can be a little tricky the old V3 boxes, with their armatures and teeth and fucking oddball trigger assembly but I love ‘em.

Anyway mate, I hope that gets you a bit closer to getting all your functions back.

4 Likes

I’ve updated the original post to include the photos mentioned. Unless I’m missing something, it seems that this particular APS AK style V3 has full auto at full travel of the selector (as pictured). I can’t seem to find full auto anywhere else on the travel of the selector.

Even notice the subtle differences like an extra tooth on the selector gear compared to your alpha king box

When the gearbox is in the blaster, what happens when you put it to the full-auto setting, or anywhere between safe and semi?

I.e fires a burst then stops? Nothing at all?

On the JM, when you move from full auto (first notch) to semi, it fires a burst on the first trigger pull then switches to semi

That’s it rattling the bits into place properly

1 Like

Yeah mine did that too. I have a feeling it could be caused by the cut off lever not lifting to above the little fin on the trolley/shuttle. When you press the trigger in ‘full-auto’, it fires a burst and only stops because the cut off lever vibrates itself to back under the trolley/shuttle then lifts it off the trigger when the sector cam hits the lever.
If that makes sense.
There’s a possibility that this is happening in this conundrum, trolley/cut off lever interface.

@Erik97, I need more pics mate, are you able to open up the gearbox and get some shots of the trigger assembly please? Specifically, with the cut off lever in the up (auto) position and in the down (semi) position. I want to see how the cut off lever end sits in relation to the trigger trolley fin.