Air Arms S200, sudden loss of power question.

[RobF]

i wonder if the reg is free flowing... can you charge the gun to say 80 bar and see how it behaves?

[Geoff555]

Hi Rob thank you. I will try that, I am just about to scrap this computer and sort a new one out, so may be a little time to reply, but I will.
Cheers.
Geoff.

[Geoff555]

Hello, thought I would have 1 last try aand ignore the setting up advise for the Huma regulator, the advise is that the 3mm. grub screw should be screwed in as far a it will go and then backed off 2 turns, well I simply wound it out until it was showing just proud of the surface ( which is the bottom of the slot in the pressure adjuster).
Hammer screw flush with face of block - 8.6 ft- lbs. 2 turns in (before this would have made little or no difference)12+ ft-lbs. Backed of about 1 turn and 11.2/3 . Yet to settle things down and lead the barrel in.
Why or how this should have happened I dont know, but at the moment quite chuffed.
Many thanks to you all for your inputs.
Will get some pellets through it and see.
Cheers and all the best.
Geoff.

[hmangphilly]

Hi geoff

so the reg manufacturer advises setting the reg by the number of turns out of a screw , rather than by a pressure reading ?


old thread i know

still interested

[Petest]

I am having similar problems but with an external regulator.

[Geoff555]

Hello I can see a bit of a mix up is possible. the screw I am talking about is a tiny alan grub screw, about 3mm. diameter. in the center of the brass screw on the end of the reg.** that sets the pressure, I believe the setting is susposed to be 2 turns up from right in.
The large brass screw is slotted for a screw driver and I wound the grub screw out intil it was just showing at the bottom of the screw driver slot. This provided a complete cure for loss of power. The only thing I can say is that it worked for me.
The VALVE spring adjusting screw was wound in to it stopped and then turned out bit by bit, on one gun, .22 it was best turned right in, on the.177 it was out1/2 turn.
** The Pressure adjusting screw, with the fine scribed line in the side, is crytical, I set mine to 95 bar on the 'paper' scale.
I have a pressure reader so I can set the bar reading accurately. Warning. A small amount can make a Large difference.
Measure the total length of the reg. with a vernier so that if things don't work out adjusting the bar setting you can always reset it to ware it was.
You are more than welcome to contact me if you so wish.
ATB.
Geoff.
This is the external Huma reg. I think the internal one is basically the same as regards settings, best to look on the Huma site to confirm.

[Petest]

Hello I can see a bit of a mix up is possible. the screw I am talking about is a tiny alan grub screw, about 3mm. diameter. in the center of the brass screw on the end of the reg.** that sets the pressure, I believe the setting is susposed to be 2 turns up from right in.
The large brass screw is slotted for a screw driver and I wound the grub screw out intil it was just showing at the bottom of the screw driver slot. This provided a complete cure for loss of power. The only thing I can say is that it worked for me.
The VALVE spring adjusting screw was wound in to it stopped and then turned out bit by bit, on one gun, .22 it was best turned right in, on the.177 it was out1/2 turn.
** The Pressure adjusting screw, with the fine scribed line in the side, is crytical, I set mine to 95 bar on the 'paper' scale.
I have a pressure reader so I can set the bar reading accurately. Warning. A small amount can make a Large difference.
Measure the total length of the reg. with a vernier so that if things don't work out adjusting the bar setting you can always reset it to ware it was.
You are more than welcome to contact me if you so wish.
ATB.
Geoff.
This is the external Huma reg. I think the internal one is basically the same as regards settings, best to look on the Huma site to confirm.

Thanks Geoff, I'll give it a go. Fingers crossed and just to clarify, its NOT the 3mm venturi screw but one in the end of the reg.

[Geoff555]

Hi yes you are correct it is NOT the venturi screw, that is unscrewed to clear the transfer port. Sorry short message laptop battery about to expire.
Cheers.
Geoff.

[Petest]

Hi Geoff

I think I have found a couple of culprits.
Firstly, there is no screw in the bottom of my regulator, I can make out the thread and feel it with a probe but no screw.

Secondly, I have taken the brass end cap with the firing valve in from off the original cylinder. The o ring was very brittle and broke while taking it off to change, same with the pellet guide o ring.
I plan to change all the seals next.
I have removed the regulator at the moment and it still varies a bit. The hammer spring adjuster isn't making a huge difference, with it flush at the rear its at 8.5, wound in as far as possible its at 10.4. Neither is the venturi screw making much difference. Even tried it with it removed and blanked off.
Seals here we come.
May be taking it to a pro for that.

[Petest]

Just another thought. Can you remember what sort of size the grub screw is?

[Geoff555]

Just another thought. Can you remember what sort of size the grub screw is?

Hi from memory its 3mm. and looks to be stainless.

Geoff.

[Petest]

Thanks Geoff and also Ta for the PM