[jweav151]

My buddy and I are stumped as to why his B2K doesn't work correctly. The manual says the input pressure should be no higher than 500 PSI, which suggests the low pressure tank he has is appropriate. However, when we try to set the low pressure regulator as the manual says, with the high pressure regulator also set in accordance with the manual, the bolt won't even slide back into firing position. When we turn the low pressure regulator up so the bolt slides back the gun barely fires; minimal velocity. So then we turn the low pressure regulator up higher to get descent velocity and the relief valve opens and starts venting air. Finally, we backed the low pressure regulator down just enough to make the relief valve close, but the velocity is barely 200fps.

We tried my high pressure tank on it but nothing changed. We've got the gun to where he can play but the manual says the gun is supposed to operate with the low pressure regulator set to 90psi and the relief valve opens at 125psi; so we probably have the regulator set around 115-120 which is 25-35% higher than it's supposed to be. I can't imagine it is good for the gun to be set that high, plus it still doesn't work correctly, so something is still wrong with it.

Our next step is to completely disassemble the high and low pressure regulators and see if something is obviously messed up, but I've never worked on an electro-pneumatic before and I don't much like the idea of my first belonging to someone else; so I'd appreciate any ideas, suggestion... anything.

[Mixednutz1]

Try this.... set your LPR high enough to open bolt/cycle gun. then adjust your HPR to get velocity. The manual is WRONG!!! the LPR controls the air pressure to allow the solenoid to control the inner workings of the gun. The HPR is controls the pressure asserted on the ball higher pressure=faster velocity. It is "not good" to crank your HPR over 500psi ... the hammering force is too much. if you find you are riding the 500psi line then raise your LPR slightly. The solenoid channels air to the ram, which strikes the valve (like the old PMI 3 or spyder design) striking the valve harder=more HPR=faster velocity ..... if you have an adjustable Dwell setting on the board you could increase the dwell value. LMK if this helps

[dynamomark]

what does the gauge on the gun say? the gauge shows the operating pressure of the hpr of course
my gauge shows 250psi (i dont know if its right but hey my gun shoots just fine)
adjust that pressure by the hpr (the thing you grab in front of the trigger)
then move on to the lpr (that thing under the barrel) turn that thing in till you hear a leak then back it out about a 1/2 turn. ok now while the gun is all aired up see if you can pull back on the bolt pin, it should be a bit hard to pull back but you should be able to get some movement. if its super hard to get movement unscrew the lpr deal a little and retest.

and take a few shots between all adjustments too

hope this helps you

[jweav151]

Thanks for the help guys. That's pretty much how we have the gun set up now. We were just concerned that we were having the LPR and HPR set so different from the manual.

Thanks again.

[63VDub]

If your regs are adjusted in the ballpark of what stock is, I have a couple of questions:
How is your battery? Have you tried a new one? Is it a stock board or aftermarket? Pull your ram and see how it moves. There should be a spring pushing the hammer forward, but other than spring tension it should be very smooth in motion. How does the bolt fit in the bore. It should fit smoothly, without excessive wobble and without binding.

Oooh, check your detent(s) if it has cocker detents, make sure they don't protrude into the breech (the housing of the detent, not the ball), that will bind the bolt and keep you from getting velocity.