qb exhaust port issue

[renowntwo]

Been have trouble getting the transfer port to seal due to the valve been misaligned. It has blown every seal out on the right side. There's not a lot of surface area for the seal to sit on. Tried another valve and the same thing so I tried another same thing. Anyone else had this problem and if so what did you have to do to correct it?
I believe enlarging the tube enough to get more surface area is the way to go because it just my thinking that if I enlarge the exhaust port I will lost more surface area. But at the same time what would it do to my chances of getting a good seal.

[rewinder]

I sent u a link for a slick fix for this problem, from another forum, as I didn't know if it OK to link to another forum.

It worked slick and will work if misalignment is side to side instead of front to rear

[renowntwo]

Thanks for your help. Will check the link out.

[Millipede]

please post the link

[nervoustrigger]

Sorry, just now saw this thread.

I think you're spot on with the idea of enlarging the hole in the air tube to expose more of the valve on which the transfer port can rest.  The easiest thing would be to just drill it larger and use a larger OD transfer port (either tubing or a piece of plastic rod with the center drilled out).  However I would first suggest taking a close look at the width of the flat on the underside of the receiver, and think about how the larger transfer port will seal against it.  Meaning if have to go really big, it may not seal against the flat. 

If that's a problem, use a rat tail file to enlarge the opening only in the direction you need.  In so doing, you may have to get creative with making a transfer port.  I'd take a piece of plastic rod and shape it to be a snug fit to the now irregular opening, drill out the center, and then cut it to length.  A length of 0.095" to 0.105" is ideal in my experience.

One last possible solution you can use if the misalignment can be solved by shifting the valve left or right or back (but not forward).  You can carefully remove a tiny bit from the head of the valve retention screw.  That will let you bias the valve slightly to get the parts better aligned.  (Or enlarge the hole where the head of the retention screw rests, same concept).

One other thing I want to mention, even when the parts align well, a transfer port made from icemaker tubing (0.25" OD, 0.170" ID) is a sloppy fit on the OD and thus can shift and leak.  I take some 0.020" thick Delrin (UHMW) tape and wrap one turn around the poly tube.  That makes it a snug fit...can turn the air tube upside down and it will stay in place.  I've used that method again and again and I can't tell you the last time I had a leak there.

[rewinder]

Link describing a fix, I used JB weld after wiping a slight film of silicone on the valve at the port, to keep the JB from adhering

http://ukchineseairgunforum.myfreeforum.org/about373.html?sid=51cc2a9c59db2d95c24318e81f1d4807

[renowntwo]

Thanks Mr. Nervoustrigger great tip about wrapping the transfer seal with the tape I never thought about that.