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Anyone know of a person who has done this? I've heard that it has to be done very properly. My JB weld has a working pressure of 900 psi. Is this something that is tapped and plugged with a bolt? I'm going to try it with thee 760 valve I have since it won't be used in any airgun now that I messed up my 760 seals. I'm going to see what it does to the broken 760 and then see if the PCP mod can continue.
Thanks
So I just read a thread saying with an aluminum valve, I can use a 2-56 tap and then use the appropriate bolt. I really don't want to take apart my 2240 or 1377 to see if the bleed hole is the same size as the 760 valve. Can anyone confirm the size of the bleed holes between the 760 valve and the 1377 or 2240 valve? That would be totally awesome!
Thanks
In an attempt to get my 760 back up to par, I added this to the transfer port...
Attachment 1082
It is the plastic transfer port from the 760. It is a blurry picture, but the white blob at the port hole is the inner tube cut from a "pen switch." I used a 3/16 to slightly open the transfer hole of the plastic port and wrapped the tube with teflon tape. I stuffed it into the port halfway and the protruding tube was cleared of any excess teflon tape. What this now does is allow the tube to fit perfectly into the Valve Transfer Hole Seal and send the air straight into the plastic transfer port. The inner diameter of the tube is exactly the diamter of the valve hole so no restriction is taking place. I hope this helps to clean up any transfer leaks. But...
I still have a bolt probe leak and a I have a few nice scratches in the valves outer O-ring and pump cup. I'm also going to just use JB Weld (High Heat 800 psi) in order to seal the bleed hole.
Any suggestions, warnings? Thanks
Well , I plugged up the bleed hole with a solid filling of JB Weld. We'll see if it blows open or not... For the breech (plastic transfer port) opening though, I'm thinking of adding a 3/16 O-ring as a breech seal. Not sure how to keep it from moving though... On the other end where the barrel meets the breech, I'm thinkin a 5/16" O-ring, but I'm not sure if that would just be a waste of time. (Maybe a thin wrapping of teflon might work just as well.) In any case, how "bad" does the valve O-ring have to get before it needs replacing? Also, should I just lightly Moly the internals of the valve when I re-assemble it?
Thanks again.
Well, I can definitely say that did restore the rifle to it's full operation plus some. It's whipping out the Stoeger X-Speeds at just under 590 fps. They are only 5.6 grains but that is still just a bit better then it was stock (+50 fps) and much better (+150 fps) after the attempted pump cup mod. I also noticed that I can increase the fps about another 50 points with 12 pumps as opposed to the normal 10. I'll keep it at ten though as right now it shoots just under legal with normal 7.3 grain HP. Valve plug is a cool mod!
I think Eric still sells a ftp kit for the 7 series: a stock valve with no bleed hole, and a flat top piston.
I've found the plugged bleed hole prone to cracking the aluminum around the repair over a fairly short period of time (this on a pump&dump build)
The S&A kit makes good sense in this respect, and it isn't that much of a cash out lay.
Regards,
Doc Sharptail
Hey Doc SharpTail! Gotta tell you, I've learned alot from reading your posts across many forums. Thanks for that. (Of course the same goes for AirGun Eric, rsterne and many others. Your wisdoms are invaluable to me.)
"I think Eric still sells a ftp kit for the 7 series: a stock valve with no bleed hole, and a flat top piston"
What!? I've been lokking online for these things everywhere! I would much rather use "stock" parts as opposed to modding them. The plug was more of an experiment to see if I could fix the busted 760, but It was mostly in preperation to mod the M4-177 I have. If I had a flat topped metal piston and plugged valve then I would just use that as the upgrade. Thanks!
Eric,so how do I order these! Send message to scopes and ammo? PM you here?
Thanks all.
Send a message through the website. The FTP kits are in short supply at the moment- need to get someone new to put them together for us.
Good timing...I'll chat with you Monday morning before you head out :awink:Quote:
Originally Posted by AirGunEric