THE EVILIRISHMAN, on 27 February 2011 - 12:40 PM, said:
I have a rap 4 A - 5 and put alluminum and metal power tube front bolt , cocking handle and polished the inside of the marker.I am a very experienced bikE builder / tech and this throws me , after all this the marker pops once and then I have to re cock it for it to fire again . I have a e grip also, the ball latch is pointing in the right direction and the cocking spring and the drive spring are in the right place , but I use some grease that I use to assemble engines to put it together with and I am wondering if that is the culprit . small chunks of grease going where they dont belong causing havoc .? The marker worked flawlessly before I did this so it is definately something I did, or didnt do right.I assembled the rear valve in the reverse way it came apart and nothing was forced together it all fit rather nice and snug.Any ideas of what I did wrong or missed? Any help would be appreciated,Thanks Tim Terminal Velocity Cycles
If it helps, petroleum-based lubricants will wreck the o-rings.
Grease is supposed to "last" longer than oil, but it gums up more easily in the cold....
Essentially, it sounds like the upgrades you put in have lowered the amount of air leaving the valve - which means there isn't enough to force the hammer back into place to catch the sear. So, 1): try increasing velocity.
2) Get a stiffer mainspring behind the hammer to compensate for the new powertube (there may be increased friction as the hammer slides into the pin at the back of it).
3) Try oil designed for paintball markers - I'm not sure how quickly petroleum-based stuff will eat at the o-rings but you'll probably get some leaks when it does.
It could just be the powertube wasn't size properly so the hammer doesn't slide in well - I had an aftermarket lightweight hammer that was slightly too big, and I couldn't get velocity over 230 fps.