Quote Originally Posted by thechemist View Post
So to cut a long story short I lent my mint Benjamin EB22 (in original box) out before first lockdown. Got it back a few weeks back, and although it was working, was covered in rust and box had been chucked out due to water damage. So after a bit of plinking, the CO2 bulb seal gave up. On stip down I found the other seals were well past sell-buy date and the valve stem spring (inside the valve assembly) was deformed and obvioulsy needed replacing. The parts for these seem to be non-existent in the UK (other than the seals), so took a punt on a crosman 2240 valve stem spring. So now I have a working pistol but the power is right down from around 5 ftib to less than 1 ftlb and I notice that the CO2 capsules are only just being pierced with a much smaller hole than before (I tried a 2240 valve stem too, same result). So it's either put in a stronger hammer spring (2240?) or try and find a weaker valve stem spring off the shelf that will work. Any suggestions would be appreciated!
My friend on this forum had a similar problem with power output. Turned out to be misalignment of transfer port between the valve and barrel. You sometimes have to back off the end of the screw in part of the valve so that it lines up correctly. Backing it off slightly does not cause the O ring to leak, and power goes way up to expected levels.

Baz