PBX Frame




The most critical part is the instructions. Make sure you follow them, or you'll damage your valve.

Installation Instructions


Known Gun Issues

The WGP BlackMagic and SR take an 11/16" valve with karnivor spacer.


Don't Screw it Up

Unlike the mQ-Valve, the MQ2 has a totally enclosed solenoid. Crushed solenoids should not be an issue, but sheared wires are still a possibility. Make sure you do not allow the pilot to rotate when tightening the IVG. With 11/16" valves, make sure the orings on the outside are lubricated well prior to insertion.


The White Spacer

This part adjusts spring pressure on the pilot seal. Incorrect use will result in inconsistency or abnormal velocity due to how the pilot works. The spring force is supposed to be mostly balanced by the pressure on the orifice. With too much spring force or too little pressure, the pilot relies more on the force applied by the solenoid to operate. The valve was designed to only require a small kick from the solenoid to open the pilot. The solenoid, electronics, and battery can not deliver a consistent large kick.  Note that the solenoid will not lift the plunger without any pressure in the valve.

The white spacer is installed by default in the pilots for two reasons. It should allow the valve to hit velocity in the worst case scenario, and it won't get lost in the packaging. It appears that many guns work better with no white spacer. Unless you have a mini body or other body with a small volume in front of the valve, I would recommend installing the valve without the spacer. If you can't hit velocity, install the spacer.


The Extra O-Ring

This particular -014 o-ring is quite important. If it is not installed on your valve, place it in the shown position before installing the valve in your gun. This o-ring acts as the seal that is normally provided by the valve retaining nut in a normal gun. If it is not installed, a large amount of gas will vent into the grip frame, causing various negative effects (see "How it Works" in the general section). Different bodies may require larger or smaller o-rings in place of the -014. Some people may even have to remove it or cut the rim on the valve body back.


Cocking Rod?

The cocking rod is actually not necessary to the operation of the gun. Its only purpose is to prevent the backblock from twisting. It also has the safety benefit of not allowing the backblock to shoot off the back of the gun in the event of a broken pump rod. Mike almost got hit in the face this way during early testing. The rod can be cut down and threaded and/or the knob at the end removed to improve the cosmetics of the gun.


Fine Tuning

Our testing has shown that a high pressure low dwell situation is the best for efficiency. However, you really can not go wrong with the standard 4ms dwell. Race users will need a higher dwell due to lower voltage. The best method for setting timing is outlined in section F of the Installation Instructions. This thread on PBNation is where people post their settings. A search through there should give you a good idea of what to expect. You may want to remove the white spacer.


Really Quick E2 Timing Setup

In a hurry? Follow this procedure. It will get you workable settings with little effort. You may still need to adjust the settings for optimum performance.

Set it to factory fast, set CON to the lowest setting, then adjust COFF so there is not any difference in sound between the first subsequent shots in 15bps ramp mode eye off.


Really Quick SR Timing Setup

It appears that the valve will just drop into an SR without any changes to timing, or removal of the white spacer. Your mileage will vary.


Race Frame?

The race frame is not officially supported anymore. They tend to be hit or miss, so we will not guarantee that it will work. It's possible to swap the bodies of the connectors to make the valve plug into the race, but you're on your own.



One of the early prototypes was run in a gun without any maintenance for approximately 100k shots. This particular valve had an unanodized aluminum valve body which has very little resistance to wear. When it was removed to be replaced with a redesigned valve, it was still operating normally. However,  the poppet was starting to get a bit sticky (no first shot drop off was noticed) and some dirt was building up inside the solenoid. A conservative recommendation is to tear the valve down every 20k shots or so. My feeling is leave it alone until it stops working right.

Wipe all lubricant off the poppet and out of the valve body. Re-lubricate with a generous amount of Dow Corning Molykote 33 grease. 33 is a low temperature silicone bearing grease that causes the seals to shrink slightly. Dow 55 is an oring lubricant that causes the seals to expand slightly. If your seals feel loose or are leaking, then 55 would be recommended. Otherwise, use Dow 33. Disassemble the pilot by unscrewing the pilot solenoid cap. Wipe off any dirt from the plunger and solenoid bore. Lubricate the end of the urethane seal, but not the rest of the plunger. The solenoid is designed to run dry. Reassemble the valve. Be careful to avoid damaging the wires when tightening the pilot solenoid cap. Check to be sure that the solenoid is bottomed out in the pilot housing by trying to rotate it with a small allen wrench. There should also be a small gap between the pilot housing and solenoid cap.

Replacement Parts

This is a list of the more commonly available replacement parts. Note that a special punch is needed to make the poppet seal.
Orings on 11/16" Valve Body 11/16"od x 1/16" -015 70 duro buna Obtain from hardware or auto parts store
Oring on Front of Standard Valve Body 1/2od x 1/16" -012 70 dura buna Obtain from hardware or auto parts store
Oring Between Pilot and Valve Body 1/2od x 1/16" -012 70 duro buna Obtain from hardware or auto parts store
Poppet Reciprocating Seal 3/8od x 1/16" -010 70 duro buna Obtain from hardware or auto parts store
Oring  on Outside of Standard Valve Body (see above) 5/8od x 1/16" -014 70 duro buna Obtain from hardware or auto parts store
Poppet Face Seal 1/16" thick 90 duro urethane Punch from urethane sheet
Urethane Dot  (end of solenoid plunger) 3/16dia x 1/16" 90 duro urethane Punch from urethane sheet and superglue in place

You can obtain the urethane sheet for the plunger and poppet seals from The smooth side of the urethane should be facing away from the plunger.

The poppet spring is McMaster-Carr part number 9435K74.

My Valve Leaks Down the Barrel!

This condition can be caused by a number of factors. Check the following items:

1. Is the IVG tight?

2. Does the valve still leak with the setscrew in the bottom of the gun body removed? If not, the setscrew needs to be shortened.

3. Remove the valve and inspect the disk seal on the end of the poppet. Is the seal off center, causing air to leak by when it's installed in the valve body? If so, center the seal and tighten the screw until the washer visibly displaces the rubber slightly. Are there any cuts or other damage on the seal surface? If so, replace the seal or turn it over for a temporary fix. The screw should be tightened until the rubber is slightly displaced by the washer.

4. Inspect all o-rings on the outside of the valve body. 11/16" valves in particular have issues with the o-rings getting cut during installation.

5. Is your body in spec? Some standard gun bodies have jam nut threads that are too long, preventing the valve from sealing. Try removing the -014 o-ring on the outside of the valve body. It may be necessary to machine back the lip on the valve body in extreme cases.



Most people's problems are timing related. Shootdown is very common, and is easily corrected by increasing the amount time the bolt is allowed to close (COFF). Make sure your tank is screwed in all the way

 If your valve does not fire, wires are intact, and operating pressure is correct, a stuck poppet is most likely. Typically you will hear a quiet popping noise from the pilot. Just firing the gun can unstick the poppet. Disassembly and relubrication may be necessary. If a valve sits unused for too long, the poppet may take a few shots to get moving. Valves that sit unused can also develop a slight leak in the pilot assembly. In this case, disassembling the pilot and removing the solenoid, lubricating the urethane seal on the plunger, and reassembly may solve the problem.

If the pilot does not pop, check all the electrical connections and be sure the back cap of the solenoid is not crushed. The solenoid should measure around 5.8 ohms. Make sure you have a good battery and grip frame. Double check your operating pressure, which should be around 250-300 psi.

Failure to fire can also be caused the 5/16" setscrew in the bottom of the gun body contacting the poppet. Check if it fires without the screw installed.

Low velocity may be solved by increasing dwell and input pressure. Additional volume in the valve chamber, in the form or a low pressure chamber or regulator with a lot of post regulated volume, is also helpful. In the case of boards that do not allow sufficient dwell or mini bodies, adding a small shim under the plunger spring to run the valve at higher pressure may help. Experimentation will be necessary.

Bad consistency- Some valves just need to be broken in. Also check to be sure the solenoid cap on the pilot is tight by attempting to rotate the solenoid inside the housing.

The cocking rod can get stuck in the spacer causing it to rotate behind the IVG. This makes disassembly of the gun impossible. The spacer can be locked in place by tightening a long screw into the rear gripframe screw hole. This will make a real mess of the spacer, but it beats not being able to take it apart. You'll most likely have to use the cocking rod to pull out the spacer after you take the IVG out. A better solution is to drill a small dimple in the spacer and use a pointed screw to lock it in place.

Polishing the inside of the valve body can help a number of problems, including sticking, first shot drop, and bad consistency. See "Optimum Performance" in the general section for a brief description of the procedure.


Custom Projects

Most of the guns mentioned in the old "Custom Projects" section are now officially supported  by the MQ2.

AKA Excalibur- Not really a cocker, but close enough. This gun is a closed bolt with solenoid valves manifolded under the body. The 11/16" version of the MQ2 should be used. In the particular example I installed a PBX mQ-Valve in, the hammer ram housing was the perfect length to hold the valve in place. The MQ2 is about .150" shorter, so a spacer will most likely be necessary. YMMV of course. A slot must be cut in the body to allow the wires to pass through and the valve to be aligned. You need to order the Race version of the valve which comes with a 1.25mm pitch Molex connector. I have no idea how well an MQ2 will perform in an excal. Apparently it is considered quite difficult to get working and there are only two or three functioning examples out there.

For those using the Tadao board, it will have to be modified to operate the mQ-Valve.


Midget bodies will need a cut down spacer due to their shorter length bottom tube.


Back to MQ-Valve General Information

 last update: 12/13/08

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