robertwalsh1981
Member
Hello everyone,
I just resolved this issue with a bunch of help from members over on AGN, it doesn't sound like it is very common but I thought it might be worth sharing what was happening and the solution here incase someone else ever runs across it.
:::::Issue:::::
A few days ago my new Ghost suddenly stopped producing power it would shoot but instead of getting ~850 - 900 FPS it was now struggling to get ~620 fps with the following configuration.
BRK Ghost .22 HP
23" barrel
Red Hammer Spring (Factory HP spring)
Tank ~190 BAR
Reg ~165 BAR (the reg was this high as I had begun troubleshooting and had been slowly increasing it to see if FPS would climb, it didn't)
PW Max
JSB Exact RS Diablo 13.43 gr.
FPS = 622 (highest)
This behavior began while I was fiddling with various tunes and had degassed the gun several times following the procedure (dry firing) outlined in the BRK tutorial video HERE to degas the gun.
Verified the following:
- Transfer port correctly aligned
- Probe O-ring was in place/intact (and lubed)
- Pellet debris not blocking hammer/spring
- Hammer was not damaged
- Increased reg pressure
- Plenty of air in the tank
:::::Solution:::::
I found that the internal tip of the valve stem (end opposite of the poppet) had come unscrewed and was restricting the travel of the valve stem.
It should look like this:
The shortcut to identifying this was:
1. Degassing the gun (I would avoid dry firing as I believe that is what caused this issue)
2. Removing the rear of the gun to expose the valve poppet
3. With the gun fully degassed (Reg gauge reading 0) see if the poppet moves when you press on it (it should move freely like in the video).
If it does not move, or only moves slightly you will need to pull the valve. I followed the steps outlined in the BRK Ghost Strip Down Tutorial and used a pair of snap ring pliers with changeable tips.
As I was pulling the valve out of the gun I noticed that there was almost no flex in the valve assembly unlike what we see HERE and it took quite a bit of effort to get the two halves of the valve body to separate.
When attempting to tighten the two halves of the valve pin it acted like the threads were galled and would not tighten, I was able to unthread the two halves of the valve stem and then cleaned up the threads as much as possible with a brass wire brush. Then I worked at threading them together working them back and forth/back and forth until I was able to get them almost tight (maybe a 1/16" gap) at which point I wrapped the poppet end of the stem in a towel and "clamped" it with a vice grip which allowed me to use a crescent wrench to finish tightening up the halves.
In the end I took it back apart, cleaned the threads and applied some Loctite to ensure that this will not happen again. After reassembling the rifle I tested it with the following configuration and results.
BRK Ghost .22 HP
23" barrel
Blue Spring
Reg ~150 BAR (was aiming for 140 oops)
PW Min
JSB Exact RS Diablo 13.43 gr.
- Chrono missed the shot, but a super sonic crack never sounded so good!
I switched over to the JSB Hades 15.89gr
Shot 1 - 1,058 FPS
Shot 2 - 1,086 FPS
Shot 3 - 1,086 FPS
Shot 4 - 1,088 FPS
Shot 5 - 1,090 FPS
Anyhow, after my discussion with the other forum members at AGN I am leaning towards the theory that my degassing via dry firing (I was doing a LOT of this) while tweaking my tunes ended up causing this issue. So moving forward I will be degassing via cracking the manometer.
I hope this info can help the next person that runs across this issue.
I just resolved this issue with a bunch of help from members over on AGN, it doesn't sound like it is very common but I thought it might be worth sharing what was happening and the solution here incase someone else ever runs across it.
:::::Issue:::::
A few days ago my new Ghost suddenly stopped producing power it would shoot but instead of getting ~850 - 900 FPS it was now struggling to get ~620 fps with the following configuration.
BRK Ghost .22 HP
23" barrel
Red Hammer Spring (Factory HP spring)
Tank ~190 BAR
Reg ~165 BAR (the reg was this high as I had begun troubleshooting and had been slowly increasing it to see if FPS would climb, it didn't)
PW Max
JSB Exact RS Diablo 13.43 gr.
FPS = 622 (highest)
This behavior began while I was fiddling with various tunes and had degassed the gun several times following the procedure (dry firing) outlined in the BRK tutorial video HERE to degas the gun.
Verified the following:
- Transfer port correctly aligned
- Probe O-ring was in place/intact (and lubed)
- Pellet debris not blocking hammer/spring
- Hammer was not damaged
- Increased reg pressure
- Plenty of air in the tank
:::::Solution:::::
I found that the internal tip of the valve stem (end opposite of the poppet) had come unscrewed and was restricting the travel of the valve stem.
It should look like this:
The shortcut to identifying this was:
1. Degassing the gun (I would avoid dry firing as I believe that is what caused this issue)
2. Removing the rear of the gun to expose the valve poppet
3. With the gun fully degassed (Reg gauge reading 0) see if the poppet moves when you press on it (it should move freely like in the video).
If it does not move, or only moves slightly you will need to pull the valve. I followed the steps outlined in the BRK Ghost Strip Down Tutorial and used a pair of snap ring pliers with changeable tips.
As I was pulling the valve out of the gun I noticed that there was almost no flex in the valve assembly unlike what we see HERE and it took quite a bit of effort to get the two halves of the valve body to separate.
When attempting to tighten the two halves of the valve pin it acted like the threads were galled and would not tighten, I was able to unthread the two halves of the valve stem and then cleaned up the threads as much as possible with a brass wire brush. Then I worked at threading them together working them back and forth/back and forth until I was able to get them almost tight (maybe a 1/16" gap) at which point I wrapped the poppet end of the stem in a towel and "clamped" it with a vice grip which allowed me to use a crescent wrench to finish tightening up the halves.
In the end I took it back apart, cleaned the threads and applied some Loctite to ensure that this will not happen again. After reassembling the rifle I tested it with the following configuration and results.
BRK Ghost .22 HP
23" barrel
Blue Spring
Reg ~150 BAR (was aiming for 140 oops)
PW Min
JSB Exact RS Diablo 13.43 gr.
- Chrono missed the shot, but a super sonic crack never sounded so good!
I switched over to the JSB Hades 15.89gr
Shot 1 - 1,058 FPS
Shot 2 - 1,086 FPS
Shot 3 - 1,086 FPS
Shot 4 - 1,088 FPS
Shot 5 - 1,090 FPS
Anyhow, after my discussion with the other forum members at AGN I am leaning towards the theory that my degassing via dry firing (I was doing a LOT of this) while tweaking my tunes ended up causing this issue. So moving forward I will be degassing via cracking the manometer.
I hope this info can help the next person that runs across this issue.
My reg was set at 165bar from factory and ya....it's definitely too hot for pellets
....Sent him flying with a violent puff of air! The Ghost is an excellent gun, I plan to keep mine forever
Maybe later this year I'll get a slug barrel!?
. No idea if that’s true. I suppose if you are going to dry fire it’s best to turn the hammer spring all the way down first.
