Air Arms S200, sudden loss of power question.

[Geoff555]

Hi all, This S200 (.22) is fitted with a Huma external regulator and has me puzzled, the pellet probe and cylinder seals have been replaced as they are a 5 minute job and no trouble.
What happened is this, running at 11.3 ft-lbs and suddenly noticed ,literally one shot to the next, that the sound had altered and sounded 'soft.' checked and it had dropped to 9.2 ft-lbs and varying. Winding the hammer spring up makes no difference, tried new spring, same.
Any suggestions would be very welcome.
Many thanks.
Cheers.
Geoff.

[Rich]

Could be muck on the striker pin, the one with the JC circlip. Or bent pin.

[Geoff555]

Hi Rich thank you, I did check the pin when I replaced the cylinder/block seal, straight, clean and free.
Cheers.
Geoff.

[spartan]

The regs probably failed.

[Geoff555]

Hi, the mystery deepens a lot, I did consider a failed regulator so I took a complete cylinder and reg. off a fully functional S200 which was a known quantity.
The result was 8 ft-lbs. So that leaves a faulty breach block, internal crack?? and a barrel problem?? The answer is that I don't know, just on the off chance it was low batteries in the chrono put in new ones, OK I was getting desperate and reaching for an answer.
As I am going round in circles, scratching my head and that hurts, I am going to leave it for a day.
Thanks all.
Cheers.
Geoff.

[Rich]

Most unlikely to be a cracked block, it's aluminium and not a very hard grade at that.

Oil on the hammer? Transfer port adjuster screw problem? Probe O ring blown off? Broken hammer spring?

If the problem persists with a different cylinder you can rule out the reg and the firing valve.

[Geoff555]

Hi thank you. Rich I am giving it a rest because I have done the following and the cure may well be a angle grinder.(Ha Ha.)
Changed the following with known bits from a fully functioning 200S which is 3 years old and has not missed a beat. The problem child is a very early one? About 2002 I think.
Complete cylinder with Huma reg ( set to 11.4 ).
The barrel.
Hammer spring. Twice, new.
Probe seal. Twice, new.
Pin, with spring.
Trigger sears and springs. New.
Hammer twice. 1 New.
All seals.

So far, last year had a slight drop corrected with a new spring.
This time was running at 11.2/1 ft-lbs. with no problems.
From one pellet to the next it suddenly went to sounding 'soft'. As if something had broken.
Brought home from range and it had gone down to 8 ft-lbs. ish. Maximum. It was varying a lot.

So the conclusion at the moment is a crack or fault of some kind in the block.
Will investigate another block but I don't think it's worth the expense at the moment.

Cheers all.
Geoff.

[Geoff555]

Hi thank you. Rich I am giving it a rest because I have done the following and the cure may well be a angle grinder.(Ha Ha.)
Changed the following with known bits from a fully functioning 200S which is 3 years old and has not missed a beat. The problem child is a very early one? About 2002 I think.
Complete cylinder with Huma reg ( set to 11.4 ).
The barrel.
Hammer spring. Twice, new.
Probe seal. Twice, new.
Pin, with spring.
Trigger sears and springs. New.
Hammer twice. 1 New.
All seals.

So far, last year had a slight drop corrected with a new spring.
This time was running at 11.2/1 ft-lbs. with no problems.
From one pellet to the next it suddenly went to sounding 'soft'. As if something had broken.
Brought home from range and it had gone down to 8 ft-lbs. ish. Maximum. It was varying a lot.

So the conclusion at the moment is a crack or fault of some kind in the block.
Will investigate another block but I don't think it's worth the expense at the moment.

Cheers all.
Geoff.
Just an add on. Hammer clean and dry. Port adjuster screwed out and clear of port.

[Geoff555]

Hi, well I think this is probably the last post until I can find a block.
I rotated the barrel 90 degrees to block off the transfer port, cocked and fired it. The result was a loud 'farting' noise that lasted for about half a second or so. HUMPH bugger.
Cheers all.
Geoff.

[Jimbob 2705]

I must confess I haven't read the entire thread, but have you tried it without the Reg?

[gc93]

hi are you power testing in or out of the stock ?, I had one years ago when it was screwed into the stock the inletting was catching on the hammer cocking bolt ..

[Enthusiast]

I had this the woodwork was touching the action on the left, 2 mins with a file and jobs a good un

[Geoff555]

Hi, well I did say the last post but to answer the last couple of your kind replies.
Testing out of the stock.
With and without the silencer.
Havn't tried without the regulator as I don't have the 'pot' or what ever it's called.
Cheers.
Geoff.

[RobF]

Not familiar with the internals of the s200...have you looked at the knock open valve and spring?

A loud farting noise suggests a lot of valve bounce. That could be because the reg isn't working as it should or because the valve isn't being closed as it should. It might be that the reg isn't getting the air it needs.

[Geoff555]

Hi Rob, knock open valve and spring are new, done so many things I had forgotten. Tried 2 regs and the noise seems to be a HP leak lasts until the plenum is empty?
Cheers.
Geoff.