Need help! Gun wont recock!

[soulhunter6]

I was shooting my JT 4 in the backyard. the gun was working fine for the first 50 shots or so but then it wouldnot recock. I would have to recock after each shot. What would be causing this and how could I fix it? Thanks!!!

[soulhunter6]

I just took everything out and when i removed the barrel the oring was extremely stretched out and loose. could this be what is causing the problem?

[soulhunter6]

when i was shooting I dont think I was low on, the pressure gauge said about 750 psi. I was using a 20 oz tank with only about 300 shots on it.

[PMI_Guy]

is this the first time youve used it? my friend had the same problem, just put a few drops of oil in the ASA (thing were the air goes in)

[soulhunter6]

I used the gun a couple weekends ago. Shot about 300 balls.. it worked fine. I amy be playing tomorrow so any help tonight would be appreciated.

[SilentTension]

replace the bolt and striker o-rings and oil it all good

[Reason]

just oil all the orings! no need to replace anything if its not broken.

[garrityplus]

Originally posted by PMI_Guy
is this the first time youve used it? my friend had the same problem, just put a few drops of oil in the ASA (thing were the air goes in)


NOOOOOO!!!!! DO NOT PUT OIL IN THE ASA adapter when you have the JT4!!!! IT"S A NO, NO.

I talked to a JT guy on the phone and he said it's a no no. so please do not do that. Just oil the striker, orings, and the bolt.

[Reason]

heres the deal, they tell you not to put oil in the air adapter because if you get oil in the pressure gauge then use it on a air tank and get a spark you will have a major bomb. I think it is good to oil your asa with 2 drops maybe ONE time when you first get your gun, then you should never have to do it again, or 2 drops AFTER every six months (almost never).

I prefer disassembling the marker then cleaning the whole thing and putting 1 or 2 drops of air gun oil per o-ring... that seems to work great and keeps everything just like new.

It's just like oil for your car.. you wouldnt drive your car without oil so just be sure to do the same for your marker.

[Reason]

ok just to make sure i was clear, never oil the asa, you can get the same result by disassembling the whole marker and cleaning and putting a drop of oil on each oring. that is all you need. the only reason you might want to put a drop of oil in the air adapter when you first get the marker is to make sure all the internal surfaces have a coat of oil to keep everything protected.

never oil the asa and always clean all moving firing parts and oil each oring after each day of playing.

the only time you should have to take apart and oil the expansion chamber and air adapter orings is if you get an air leak for some reason.

seem reasonable and clear to everyone?

good ;)

[derek]

the same thing happened to my 3.0. what you do is take off the grip frame and under the gun is a screw. the screw controls the presure so if you un screw it a little it should work.

[MyJTRox]

The 3.0 and 4.0 aren't the same, I don't believe that screw is there on the 4.0, cuz the 3.0 has the gas thru grip, not an expansion chamber.

[Icefire]

Originally posted by derek
the same thing happened to my 3.0. what you do is take off the grip frame and under the gun is a screw. the screw controls the presure so if you un screw it a little it should work.

I think that screw under the frame is to hold the valve in place and not to adjust the pressure.

Anyway, let's get back to fixing the recocking problem. Yes, the recocking problem is cause by the bad o-oring, but the question is "What is tearing up the o-ring?" Will, the anwser is the feed tube and the sight rail screw taps. If you put your finger down the feed tube and feel around there, you will (might) feel something sharp/rough. That is one of the cause. The next is the screw tap for the sight. Take the bolt off and put your finger into the tube and feel where the screw tap is. Is rough isn't it?

Well, to fix it is pretty simple. Get some sand paper - 400 and 600 wet dry. Take a small piece of the 400 and sand it down little and then clean it up with the 600. DO NOT OVER DO IT WITH THE 400, you'll may kill the gun if you take it down too much.

Another way to take care of this is just to polish the top tube of the gun. Get a plastic hanger, drill, some rag, and metal polish. Take your gun apart. Cut the coat hanger and attach it to the drill. Attach the rag to the other end of the hanger. Put some metal polish on the rag and polish the inside of the tube. When finish, clean, replace o-rings, oil, and re-assemble the gun.

Problem solved!

[soulhunter6]

when i check my bolt the o-rings look fine. There is some scratching on the top of the bolt, at the very end,(going into the gun). Still not sure of what te problem is though.

[Reason]

burrs

burrs are like little metal hangy things that are made when metal is machined you can feel them as being rough on the edges of machined billet parts (like the firing pin) also if you rub a q-tip cotton swab along and edge of a metal part and it catches the cotton that is a rough edge/burr.

before i ever even used my jt4.0 i deburred the firing pin around the hole and clearance slot for the ball stop, also around the chamfer that comes in contact with the ball. this is to prevent these burrs from coming loose and causeing havok with the firing pin and its clearance, o-rings etc. its just like if you had metal shavings in the motor of your car. :) Also I deburred all the threads on the barrel and low pressure chamber.

[Reason]

oh and to get burrs off, use a xacto knife and very gently rub/slice them off.. you could also use a very very fine file or very fine sand paper. As with any thing its important to know what you are doing or you could cause more problems than the ones you are trying to solve.