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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: Airgunhunter73 on May 26, 2019, 07:44:38 PM
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Hey fellows my modified bulldog with the gen 1 JSAR balanced valve is leaking air out the barrel, I tried cocking it but no luck there had it out to the range about a week ago an it was filling and shooting fine went to shoot it today and it was empty of air so when I tried to fill it, it just blew air out the barrel so I cocked it an it continued to leak an not take air never had a problem like this with it before all thoughts on this would be appreciate as I haven't had time to tear into it and won't till Tuesday. Thanks in advance Terry
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If it's coming out the barrel that means it's coming thru the vavle, so my guess would be the poppet not sealing.
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Hey Rich that was my thought also but figured I'd some of the more knowledge folks before I tear into, must be my week I'm having the same problem with my Corsair 308 :-[
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Flow air into the fill, even 100 PSI will do
Then while the air is flowing cock and fire it.
It probably will seal
Sometimes you have to block the barrel too by loading a slug or by putting a cork in the muzzle (on the Bulldog or Pitbull you might have to pull the shroud to do this - depends on how you have it configured) flowing in air and shooting it so pressure builds up and dropped off through the valve. Please aim safely if you loaded a slug and make sure it shot out if that's the method you used (I was told this by another Bulldog owner and it worked but I had to take a cleaning rod and push the slug back to the rear, fill the rifle fully and shoot it for real into a backstop... But the valve did seal the first time, just not enough pressure to fully shoot the bullet)
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Carl thanks for the information I'll try that tomorrow I really appreciate the help was hoping not to have to take it apart again so many dank screws. lol
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If the already posted ideas don't work, then the poppet stem is probably frozen in the shaft in the open position. Some of the JSAR ones have so close tolerances, they can get stuck. I know, it happened twice to me. Then finally, if you had it stored with over pressure, the poppet could have cracked. This can happen if you stored it around 3000 psi, and then it got hot, driving the pressure up.
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Thanks David I general store it at a lower pressure after I've been shooting I'll try Carl's method if that doesn't fix it I'll take it apart an see what's up and report back on my findings appreciate all the help.
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Well guys I took Carl's advice and cocked an chambered a round had it pointed into my boolit trap and it took air filled up to 3000psi and fired it, and it went brrrrrp but held air so I filled back to 3000psi took it outside to try the 125gr NOE BBT HP first shot brrrrp second shot brrrp first time it's ever done that seems like I read something about that happening to someone else?
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Sounds like hammer bounce from a too heavy hammer and a too easy to open valve.
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Thanks Wimpanzee it's never done that before but I'll back it off and see if that cures the problem.
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Well I backed the hammer spring off 4 turns and it's still doing the same thing brrrp, I don't know what else to do.
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Well I backed the hammer spring off 4 turns and it's still doing the same thing brrrp, I don't know what else to do.
I didn't mean the spring tension, but the weight of the hammer itself. My marauder used to do the same thing, with my cobra valve and stock hammer. using a lighter weight hammer (hill, 30gram) prevented the hammer bounce from having enough force to re-open the valve.
Not sure what the exact recipe for the bulldog is, but if it has a SS valve, it might need a lighter hammer.
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Sumatra Air Rifle tend to have the same issue normally its the poppet collapsing into the face of the valve and been pushed into the valve body this causes the air to leak out the barrel and when you try to fire it the gun will almost have no power because the poppet isn't moving freely and cant open properly
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Something wrong with the balancer piston or o-ring. Time to take it apart.
Could be damaged O ring and it has gotten piece missing that has blocked the balancer passage.
Or debris in the air that has damaged the valve seat. If it's the air it could affect both of your guns.
Marko
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My bulldog with the jsa balanced valve started making the burbing noise and dumping air after about 60 rounds, I never did figger out what the problem was ,installef the stock valve now no problems, sent thw valve to matt haven't heard back from him yet.
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Hey Fellows
Well I've had it apart 4 times today clean the valve up and everything else the stem was sticking in the valve so I clean the stem with some emery cloth not to much put it together it worked for 5 shots and then wouldn't shoot at all so I called Travis he told me to chuck it up in my drill and use emery cloth to polish it down some so it would just fall out of the valve I did and it did fall out freely put back together 8 shots it quite shooting again, so 4th times charm I took it back apart and put the factory valve back in it I'll try that tomorrow an see what happens fingers X. Just want y'all to know I appreciate everyone trying to help me out with this problem.
Thanks Terry
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If the valve is sticking then there could be silicone in the stem bore. Silicone and aluminum against steel stem is a big no no. It wont lube that combo, it will seize. Some ceramic lube like Krytox will work on the stem.
Marko
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Thanks Marko I had used silicon on the stem but after I spun it in the drill I used alcohol on a Qtip to clean the valve and stem before putting it back together I didn't put anything on the stem so maybe being dry wasn't good either I do have some Krytox, I'm going to see what kinda numbers I get with the factory valve and see if I in counter any problems and then try the JSAR valve again an put some Krytox on the stem. Thanks for the advice on the Krytox wasn't sure about using it on the valve stem.
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Well guys I put the factory valve components back in and the results are it's shooting great so far I'll continue to work on the JSAR valve and try it at a later date or maybe just sell it. I shot 3 5 shot strings this morning over the chrony an here's the results. So my conculsion at this time is a 2900psi fill is the best with the factory valve setup and now to the range for accuracy testing when I have a dry day. Ironman by what Travis told me yesterday the bulldog valve has a lot of anodising so you have to spin the stem in your drill using emery cloth for the stem to work I'm guessing I didn't turn it enough maybe later.
NOE 148gr cast HP NOE 124gr cast BBT HP Aeromag 128gr HP
1-791 3100psi 1-926 2900psi 1-907 2900psi
2-881 2900 2-912 2700 2-895 2700
3-843 2800 3-892 2500 3-863 2500
4-833 2500 4-855 2250 4-829 2250
5-813 2300 ending psi 5-823 2100 ending psi 5-819 2050 ending psi
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Here's a before and after pic of the NOE 358 152gr HP mine's dropping at 148grs shooting into my muddy backyard at 25yds.
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Well fellas went to the range today for a little shooting here's some pics of the Bulldog at 25 and 50 yards, they kept the 100 yard line filled up today so I'll try for next week.
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are you weighing your bullets?
I found that having all the bullets weigh within 1 grain on a 148gr bullet to helps tighten groups in the big bore airguns.
this is especially true to find and cull light bullets that have void bubbles inside the bullet because not only will they cause a point of aim shift in impact from the different weight being propelled/launched inside the barrel by the air they will not fly true being off center in rotation , like a tire out of balance. And the longer the distance the more they become fliers
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I usually weight my boolits but I don't think I had done that with these 148gr HPs and the 130 grainers were given me so I forgot to weigh them also, thanks for the advice I learn something about this sport all the time reading the posts you fellas write about your experiences they are so helpful Thank you .
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To add to someone else's issue with burping.
My bulldog with jsar valve is exhibiting this issue with each shot which causes 800-1000psi per shot. I was sent a new poppet but the same issue persists.
Anybody know how to resolve this issue? Very frustrating.
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I did change o-ring lube on the poppet to the Ultimox 226 lube and that seemed to help. I really think the poppet stem is binding a bit on some rifles and causing hammer bounce.
But I also changed the spring after talking with Oldpro on the phone about changing the orifice to get a different curve and he mentioned taking the stock spring and cutting TWO COILS OFF and using it.
I had occasionally gotten the burping but since modifying the origional spring it's never happened again.
But I can't say which was the solution since I did both at the same time.
FYI - I get a higher FPE first shot but then a declining string, not as flat a curve as with the SS valve spring.
NOTE - he warned me that using the factory Bulldog spring full length would destroy the poppet fairly soon. It has to be shortened.
Call JSAR, Travis is a good guy and will help you. He's helped me on several Marauder issues and with the Bulldog/Pitbull issues as well.
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JSAR sent me a replacement poppet but it didn't solve the burping issue and still wastes air. Still hoping to hear back for a solution. Any ideas of what the problem could be?
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JSAR sent me a replacement poppet but it didn't solve the burping issue and still wastes air. Still hoping to hear back for a solution. Any ideas of what the problem could be?
send it to matt & paul @ pitbull airguns, they will get it right !!
the previous owner of mine said it came from that direction and had problems....
i sent it to matt and now its a great shooter with much more power and consistancy ;)
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Well I have since removed the SS valve and installed the original OEM back and no more burping issues. I'd prefer not to send the rifle off as the issue is 100% in the jsar valve.
I was hoping to get a replacement but unfortunately weeks have gone by and I haven't heard anything back.
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Which hammer spring were you using with the SS valve? The JSAR one or the 2 coil cut off Benjamin one?
As I said in an earlier post, I am getting good performance with the SS valve and it's no longer burping BUT I had to go to the modified spring.
Pitbull does not recommend using the SS valve as they could not get it to shoot consistently BUT those of us who have tried it in our Pitbulls WITH the right stem polish, stem and poppet lube and hammer spring mod are not having problems any longer.
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Ive used both the supplied jsar and OEM cut. Both springs exhibit same burping issue. Brand new poppet did not fix the issue either.
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To add to previous, burping issue with SS Valve began after approx 800 shots.
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Hummm
One last 'fix' is to take out the jet on the valve and use a drop of solder to close the hole then redrill smaller which is another thing I discussed with Oldpro but did not have to do as my problem was fixed with the other steps.
{Or buy a new one, I think it's a watercraft or snowmobile jet????}
Don't remember the size he recommended, call him / Travis to get it, he really treated me well on this issue.
And my Pitbull probably has very close to 2000 shots since I installed the SS valve and solved the burping issue.
[ I shoot 4ea, 60 min SCBA tanks down each week at the range on average. Have to buy 40 lbs lead every month to keep up with the casting/shooting!]