Theoben Rapid Forum
kevG Lathe work undertaken => kevG section => Topic started by: JoeB on June 10, 2026, 10:57:26 PM
Hi all. I used to frequent the old forum a lot, but admittedly I have not been on here for a good while. I have a .177 late rapid with quite a few of kevs bits incl micro reg core. Double tap inertia hammer setup and until very recently one of kevs valves. I had a leak a few weeks back and bought a new seal kit but it has been that long since I last needed to service my gun I managed to break the valve. I dug around in my box of bits and found an old valve and fitted it. However I now have a really weird problem whereby without a pellet the gun sounds normal but when I have a pellet loaded the gun sounds louder and I think i can feel air blowing back around the probe. Its making the same power it was before approx 11.5ftlb. Any ideas why the gun should be louder when a pellet is in the barrel? - I have a LH block so a std valve wont work as the locating hole is on the opposite side and previously kev has made me valves for this gun. Im not adverse to sending the gun to kev for a checkover and new valve if its not something silly I'm missing. - I did message kev on a mobile number I have but ive had it about 15years so could be changed by now. Thanks for any info or help! Joe. (Formerly JoeB_MFR on the R7OC forum)
***Update: browsing through the forum i found an old post about the double tap inertia weights. It looks like the front pip is threaded into the brass section with the inertia weight inside? My double tap appears to be worn out as the front pip isn't threaded to the brass section.. - Kev. Is there any chance I can send you my hammer/double tap assembly for repair and also order a new valve? Cheers
Sounds like something just got disturbed, or your new old valve may be a different bore,
just do the tissue paper test, & if it's blowing back past the probe check & reseat the barrel to a mag, then check & reseat the probe to the barrel.
Quote from: angrybear on Today at 01:07:20 AMSounds like something just got disturbed, or your new old valve may be a different bore,
just do the tissue paper test, & if it's blowing back past the probe check & reseat the barrel to a mag, then check & reseat the probe to the barrel.
Thanks. Did more playing today and it was blowing back past the probe. Weird as it didn't do it previously but can't complain as I have never adjusted the probe in my 15yrs of ownership. I tightened it up a bit and now all seems back to normal. Although I'm still not 100% sure whether the double tap hammer is 100% OK. - Kev, is the small pip with a spring on it supposed to be fixed into the brass body holding the inertia weight inside? Mine is loose when the hammer is disassembled