AOA Huben parts gun turned out to be simple fix

[Pale_Rider]

First of all, a big THANKS to AOA for making this deal available. I bought a huben that was labeled a parts gun. Description said it had a leak and was not cycling. I figured if I couldn’t fix it someone else could. And if they couldn’t I would have extra parts for the huben I already owned. 
After receiving it I dry fired it a few times. With each shot the reg pressure would drop but not replenish. For the first few shots the mag cycled properly. Once the psi got low enough, there was not enough pressure to cycle the mag. Fired it until there was nothing left and the reg still wasn’t refilling the plenum. 
My first thought was a bad reg. Cool feature with the huben is you can disengage the reg thru an external adjuster. Once the reg was bypassed VOILA! she was breathing air just fine. Shot a full mag thru her with no cycling issues. Accuracy isn’t great but that’s probably because it’s not dialed in like my original huben. Man I thought I was gonna have to break it down and change out o-rings and other parts. This was stupid simple to figure out. Thanks again AOA!

Now my only problem is deciding whether I want to get a new reg and convert it to be a traditional rifle with a walnut stock OR make it into a pistol without a reg

 

[Odoyle]

Try filling to 3000psi or less and see if the regulator responds well to less fill pressure.

 

[Pale_Rider]

I filled it to 3k when I first got it. I’ll try the lower pressure thanks

 

[MacGyver]

Try filling to 3000psi or less and see if the regulator responds well to less fill pressure.

Are you thinking weak pressure on the other side of the reg?

 

[Odoyle]

Lowering the max fill air tube pressure Under 3000psi the more consistent and reliable the reg. Goes for Any brand not only Huben but not too many know this little secret! Only accuracy fanatics and long range shooters do it. Most regular airgunners dont need consistent sub MOA for casual shooting and want to fill to max pressure anyway for more shots.

 

[MacGyver]

Interesting. I was just wondering if that was due to insufficient spring pressure. For instance on the Huma external/in-line regulator, if you want to create a constant pressure greater than the 250 Bar they mention, you have to change the orientation of the spring stack to handle that extra pressure. They do state that you want to use the spring stack configuration that is as close to your target pressure as possible. That made me wonder if legionair's spring configuration wasn't providing enough back pressure for the higher air pressure, or if it was due to something else.

 

[Pale_Rider]

I tried setting the reg at 110 at first and after a 6-7 shots it depleted all the way down until it dumped out all the air. That’s when I bypassed the reg