NPAS adjustment

[Pinard]

Hey, just bought a WE scar, and I want to know how to adjust the NPAS valve since I run CO2 mags and its probably too hot for games

Yes the NPAS is installed, but NO I don't know how to adjust it !

if somebody could make a video for me or a photo tutorial I would be glad, since I'm not really good to read english so explanations would be tough to understand for me :S

[SniperSam]

YouTube - Evike.com - RA Tech NPAS kit for WE GBB
That might be it, but the commentator speaks in accented English, good luck

[Pinard]

Yeah I saw that video...but I stil can't figure how he adjust it...

[Ballcancer]

You have to hold the actual float valve inplace while you turn the adjustment nob with the provided key

[Pinard]

thank you, so I turn the knob and when I see what is moving, this is the float valve that I have to hold in place while turning ?

thank you and sorry for my noobness lol I just don't want to break it

[m102404]

The adjustable float valve assembly is made up of 2 main parts:
- the "cage"....which is the unit that moves back and forth and actually plugs the nozzle when the action starts the recoil cycle
- the adjustment part...which is a stem with a plate on one end and a male hex head on the other. The adjustment part screws in through the bottom of the cage and the tip of it is sitting in the nose of the nozzle

(simplified...the only difference between the stock float valve and the adjustable one is that there's the adjustment stem threaded through the cage)

To adjust, you turn the stem clockwise or counter clockwise.

To reduce the FPS you need to end up with the cage more forward towards the nozzle tip. To increase the FPS you need to end up with the cage positioned further back away from the nozzle tip. Basically as you screw the adjustment part in or out of the cage...it forces the cage to sit further forward or backwards.

To adjust the setting, use your fingernail and "pinch" the cage through the nozzle body to hold it in position. Then insert the adjustment key down the tip of the nozzle until it engages the tip of the adjustment stem. Turn in the appropriate direction. It may be stiff to adjust...that's a good thing.

You can also use a small/thin allen key and position it through the nozzle body and cage so that it jams things up and stops the cage from rotating as you turn the adjustment stem.

That should be clear enough. If it isn't...get someone to show you in person.

[Pinard]

thank you, I should be fine now ! if not...I'll find someone to show me, but I'm pretty sure I understand this, I'll try it when I'll have a chrony

[m102404]

Oh...forgot to mention.

The adjustment to go from 400fps to 350fps is very slight...it's not much of a turn at all. The major adjustments are getting it into that general range to start.

Also...getting it to shoot reliably under 340fps (i.e. 300-330 to be safe indoors) is pretty tricky....the valve is almost closed at that point and the gun is pretty much choked off.

[Outcast569]

Originally Posted by m102404

Oh...forgot to mention.

The adjustment to go from 400fps to 350fps is very slight...it's not much of a turn at all. The major adjustments are getting it into that general range to start.

Also...getting it to shoot reliably under 340fps (i.e. 300-330 to be safe indoors) is pretty tricky....the valve is almost closed at that point and the gun is pretty much choked off.

potentially stupid question. With it choking off the gas like that would you get more shots per fill with that or does i just bleed out the excess some where else?

[m102404]

This gas system is not "pre-measured". It's reactive. Once gas pours into the system, it keeps coming in until the very end. The redirection of the gas from the shooting phase to the recoil phase is dependant on the BB leaving the muzzle...the recoil phase is essentially fixed....so with lower velocities, you are using less gas per FULL cycle (shoot-cycle-ready for next shot).

I suspect that with heavier BBs, you'd use more gas per shoot phase as well...since the BB's stay in the barrel longer vs. light BB.

I suppose in the end you'd get more shots per mag....since less is going down the barrel.

But I suspect that it would not be significant (i.e. maybe a couple of shots, but not another full load of BBs).

Most guys top up gas when they reload BBs.

Hope that's nicely confusing...(works just like a TM gas pistol...look at Redwolfs picture write up of how a GBB works).

[coach]

With the WE PDW, if you 'choke' it too much, the recoil is severely lowered and most times won't do a complete cycle. Also will kind of sound like the mag is almost out of gas and won't lock back when empty.

[m102404]

That's because its jamming isn't it? The BB's not making it (or barely making it) down the barrel at that point. The pressure difference in front and behind the valve is marginal so it's not closing fully...causing it waffle in the change over of the cycle.

If you open it up a bit from that point...it smooths out right?

[coach]

Honestly, I haven't gone back to tinkering with it. I swapped it out for the stock nozzle my last game since the velocities were raised to accommodate gas guns. I do need to fine tune it again but having a spare bolt makes things easy for swapping back and forth.

I still need to file down the front lip a tad to relieve some of the issues I was having. The npas nozzle I have is a tad larger at the tip which gets stuck. I thought I fixed it by swapping the orings for the stock one that are smaller in OD when installed but realized at a game that the charging handle was still hard to pull back.

[MilanWG]

I just got a npas for my we scar.
Is it an easy part to install or should I let some else do it?

[coach]

Did you get the complete kit or just the nozzle? The complete nozzle and SS rod cuts the install time to a minute or two tops. Replacing just the nozzle is a little more involved but it's still super easy. Watch the video and give it a go. Just take your time and follow the steps as they do.