ugh, minimag chuffs, then doesn't do anything

[mudpie]

Well I'm a mechanical engineer and love the design of my new micromag.

I can't get the darn thing to work though, for more than a couple dozen shots.
Minimag valve, 4 stars, lightly used.
CO2 via remote line, no expansion chamber but I'm keeping it vertical (will go HPA once my the used tank I bought is hydrotested).
Level 10...recalibrated it based on what I've read here and badmovies' advice...did go from 0 to 1.5 to reduce friction with no leakage down the barrel. That didn't fix the problem which is:
Fires okay for 10-30 not very rapid dry shots, then it starts chuffing sometimes, then every time, then it doesn't fire at all or lets out a wimpy chuff.

Other people have had the chuff problem, but not usually the doesn't-fire-at-all problem. In a few hours, I try again and it works...for a while, then chuffs...and then stops working again.

It is pretty evenly oiled, and I've tried the red/medium spring too (came with the long spring), and all the seals look good. This gun has barely been used.

I would suspect CO2 stability issues, except I am running remote, and not firing more than a couple bps dry. Is the regulator so sensitive to input pressure?? Some people say it MUST get at least 850 psi, and I doubt CO2 tanks supply that. But come on, I'm not even rapid firing...wouldn't the pressure restore in a few seconds max?

Sorry for the novel. ANY help is appreciated.

[TwilightG]

I can definitely sympathize with you...

I've had an almost identical problem w/ a MiniMag I bought over eBay.
It turned out that a majority of my problem was a badly tuned level 10.

The reason why it may stop firing altogether is because the bolt might be sticking. Just place a pen in the breach and see if you can reset it by lightly pushing on the front of the bolt.

Unfortunately, I don't have a guaranteed solution for you since I am still having the same problems, just not as frequent as before. I am still waiting for a few level 10 parts that I ordered and hoping that it clears everything up.

Please let me know if you find anything... I'm sure I am having the same problem.

Just to let you know, I am using HPA w/ a factory-set output of 850psi.

[Pneumagger]

Well I'm a mechanical engineer and love the design of my new micromag.

Welcome... that is why I love mags too.

Some people say it MUST get at least 850 psi, and I doubt CO2 tanks supply that.

Some people are lemmings. Your dump chamber shouldn't be operating anywhere close to that. Closer to 350 actually. IIRC, the classic valves are reccomended at 650psi nput and the RT valves are reccomended 850psi, but both these figures would be for consistent fast performace. It will still continue to fire at velcoty until your input pressure falls below the reg output pressure, but as you dip under the reccomended input the recharge rate will be hurt.

What size CO2 tank are you using? It may be possible with something small like a 9oz you are chilling the tank and co2 is actually making it into the gun. But that would be unlikely with a remote. Just ake a modular approach to the problem... While your tank is being hydrostat'd, pick up an L7 bolt and assembly for less then $20 used and swap out the bolt kit. If the L7 bolt works well, then you know your L10 needs tuned better. If the airtank comes back and works well then it was a CO2 problem.

Bolt stick may be the culprit though. Be sure the L10 oring is not overly snug. It should slide easily onto the bolt center, but seal around. It's a high durometer oring so little crush is needed, and due to oring variations and different carriers this fit can be achieved with several combinations. I like to pick one oring at a time and run it through all the cariers sequentially, keeping note of which oring matches which carrier for the fit. Then I choose the combination that used the largest carrier - meaning as the oring wears down, instead of replacing it I can just bump down a carrier size using that same old oring prividing shorter wear in period. I call it the "Oring centered approach"... keep the oring constant and vary the carriers.

Also, some mags have problems with overtightening the screws or undertightening them. Lightly wrench tighten the front screw so it is secure, no need to torque hard. And the back screw should be thumb tight enough that you can remove it with your thumb but wont back out during play. Mags are high tolerence guns which provides rock solid reliability and performance, but at the cost of higher user error.

GL, keep us posted!

[mudpie]

Welcome... that is why I love mags too.

Some people are lemmings. Your dump chamber shouldn't be operating anywhere close to that. Closer to 350 actually. IIRC, the classic valves are reccomended at 650psi nput and the RT valves are reccomended 850psi, but both these figures would be for consistent fast performace. It will still continue to fire at velcoty until your input pressure falls below the reg output pressure, but as you dip under the reccomended input the recharge rate will be hurt.

What size CO2 tank are you using? It may be possible with something small like a 9oz you are chilling the tank and co2 is actually making it into the gun. But that would be unlikely with a remote. Just ake a modular approach to the problem... While your tank is being hydrostat'd, pick up an L7 bolt and assembly for less then $20 used and swap out the bolt kit. If the L7 bolt works well, then you know your L10 needs tuned better. If the airtank comes back and works well then it was a CO2 problem.

Bolt stick may be the culprit though. Be sure the L10 oring is not overly snug. It should slide easily onto the bolt center, but seal around. It's a high durometer oring so little crush is needed, and due to oring variations and different carriers this fit can be achieved with several combinations. I like to pick one oring at a time and run it through all the cariers sequentially, keeping note of which oring matches which carrier for the fit. Then I choose the combination that used the largest carrier - meaning as the oring wears down, instead of replacing it I can just bump down a carrier size using that same old oring prividing shorter wear in period. I call it the "Oring centered approach"... keep the oring constant and vary the carriers.

Also, some mags have problems with overtightening the screws or undertightening them. Lightly wrench tighten the front screw so it is secure, no need to torque hard. And the back screw should be thumb tight enough that you can remove it with your thumb but wont back out during play. Mags are high tolerence guns which provides rock solid reliability and performance, but at the cost of higher user error.

GL, keep us posted!

I do have a box of Level 10 parts to try, luckily.
I am/will take a modular approach, but I'm also playing my one time per year this Sunday...won't have Level 7 by then...my darn tank might not even be hydro'd by then...so I'm faced with buying a new HPA tank, renting an HPA tank, or perhaps buying a 20oz CO2 tank (that is cheap enough to try I guess). Any possibility this is other than a Level 10 or CO2 issue though?! I'm *almost* willing to throw money at a new Minimag Level 7 bolt from AGD at this point, if that might help.

Anyhow, I did go from a 0 carrier to 1.5. I tested a 2.0 by hanging the bolt from it but that was very loose and didn't come close to holding the bolt up (badmovies' suggestion)...didn't try to see if it would leak, but sure looks like it!

Also I just noticed the regulator is not perfectly aligned...I can pretty easily rotate it a few degrees past where the word 'MiniMag' is lined up. That shouldn't matter though...?

I will try loosening the front grip frame screw, and not tightening the back thumbscrew too much.
Again though, that shouldn't cause this 'gradual' problem I'm having of going from firing, to chuffing, to nothing...and then back to okay after a few hours.

[Spider-TW]

I think it might have been badmovies that was talking about the weather effects on the level 10. Maybe the lvl 10 oring is tightening up as it cools down. Try the next size larger carrier, and if it is leaking, shoot it a few times to see if it quits.

Another guy had the front/back frame screw torque problem that pneumagger mentioned. It had similar symptoms, but I can't understand how.

The reg backs rotate a little in their lock slots, it's no problem. It will make your velocity drop by that much because it is backing out the spring pack, but it will not go any further (as long as you don't machine off the locking pin ).

[Badmovies.org]

The times I have seen issues like you describe the most common cause was too tight of a Lvl 10 o-ring carrier. Did that at least correct your inconsistent velocity? If not, how is your paint to barrel match? That can cause velocity problems.

Let me see some more ideas:

Inconsistent air provided to the valve. (Try another air source, especially HPA.)

Worn out bolt spring. (Replace the bolt spring. They are cheap, keep a few extra red and silver on hand.)

Dirt, gunk, or teflon tape inside the valve assembly. (Disassemble and clean, relube with something good like KC Trouble Free oil. I always keep one of the o-ring parts kits on hand.)

Pneumagger's suggestion of making sure that the grip frame screws are tightened equally is an excellent one. I have seen that cause bolt stick. I put them in snug, then tighten 1/4 turn, though I have seen some do 1/8 and they never had a problem.

[Pneumagger]

The frame screw thing is kind of a last resort. But if you feel you've tightened them enough to knock the valve/body concetrity out of alignment, try playing with them. All my mags (especially ULE) had this problem if I overtightened.

[pierce]

I'm going to guess that you are screwing the remote in too far and blocking the flow hence giving you 20 shots or so now, then later another 20.

[Coralis]

I agree with Pierce try backing off about a half a turn on your remote knob and give it a shot

[mudpie]

You guys are awesome with all the suggestions!!!!

I did try backing off the remote's on/off...no luck there but thanks, great suggestion.

I also caught AGD's tech support and he was very helpful though said much of the same things you all said.

Here's my plan:
Try larger Level 10 carrier to see if it leaks for a few dozen shots then stops leaking (indicating that indeed, the CO2 is shrinking the o-ring temporarily).

GET my damn HPA bottle back from hydro-test and use that.

Replace all the o-rings, especially if there are any brown ones (really old!).

Clean up the inside of the valve while changing o-rings, make sure no debris got jammed in there.

Adjust screws, replace main spring, lube & clean everything.

The tech was SURE that that should take care of it!

Any other ideas are welcome!

[Badmovies.org]

If it still has a problem after you go through those steps, I think I'd have to actually hold the marker in my hands to be of any further help.

I wanted to mention that I love the KC Trouble Free oil. At one point I stored my old classic Automag for years (after oiling it) and when I took it apart to see how things looked, the o-rings were great. They had not gone bad. The KC makers claim that it keeps o-rings good for a long time, but I had to see it to believe it. I have seen some markers that were unused for years and that is not kind to Automag o-rings.

Since that discovery, it is the only lube I use.

[Coralis]

unscrew the valve halve and pull out the regulator Pin (not the piston) pull out spring too and look for obstructions in the air path check to make sure the spring isnt collapsed/broken also check for debris in the hole leading to the on/off pin (a can of air can be a good tool here just wear eye protection just in case).

[mudpie]

Thanks everyone!


In the end, I believe CO2 was the culprit. Despite running a remote, I did NOT have an expansion chamber which is recommended by AGD. Last night I got a loaner HPA tank. First I fired the gun using CO2 until it chuffed and then didn't fire. Then I switched the CO2 tank for an HPA tank and it fired again. This tells me the CO2 did NOT shrink the powertube o-ring (no liquid CO2), but rather that the regulator stopped working after the 9oz tank's pressure dropped a little from simply getting cold. The AGD technician said the reg needs 800 psi or it'll give squirrely output at a minimum. Pretty sensitive regulator, because I hadn't fired many shots, plus it was about 70 degrees ambient! This all indicated that maybe the regulator seat and regulator piston o-ring were worn and causing the reg to be extra sensitive to input pressure.
SO, though things were working okay with HPA, velocity wasn't mega stable (and I want to have the option of using CO2). SO, I replaced 6 o-rings and the regulator seat (didn't want to re-break-in a new level 10 powertube o-ring so didn't change that) and cleaned things up inside (didn't find any obvious debris). It really wasn't hard, nor did it take long, and some of the o-rings I replaced were rather brown colored indicated they were many years old. They were NOT cracked or dry or flattened, so I still think this mag has barely been used. Anyhow, I'd say VERY worth it to learn how to change out the seals. Took less than an hour with me being careful and deliberate and cleaning things as I went.
BUT after that, I had a MASSIVE leak between the regulator and valve halves which, after a rather frustrating half hour, turned out to be a tiny strand of cotton from a Q-tip that was caught in the o-ring. I guess at high pressures, even a .001" strand of debris will create a huge windy leak!

I'm impressed that a complete overhaul only needed: allen wrench, adjustable wrench, screwdriver, paperclip, oil, Q-tips (which were a pain because they released strands...).
The upside of all of this work and reading forums and reading manuals is and trying to get my mag to work is: now I know the thing inside and out. I understand how it works and can diagnose and repair any problem without manuals. And I can calibrate the Level 10 in no time at all! I can now leap tall bunkers in a single bound and take out 2 opponents at once around blind corners without looking.
But really, I'm comfortable with this marker now.
Thanks again for everyone's help!

Badmovies: Hey I use KC trouble free also! Didn't realize it 'til I pulled out a 5-year old bottle of the stuff. I agree, my gear sees little use, sits around for 1 or 2 years at a time, but works with little seal degradation.
TwilightG, I hope you find the problem. Try doing an overhaul like I did. It is easy and worth the learning.

[LoveMyMagMoreThanYou]

I hate to post this sooo long after the last post, but I have to also give a shout out to KC Trouble Free oil. It is the best. It is the ONLY oil I'll use. I have used it almost since I started playing 12 years ago. I have not experienced much wear at all. I've had my 'Mag for 8 of those years and I've changed the orings in it ONCE. I don't even really know that I needed to then.....

Good luck with your 'Mag issues. I'm having the same trouble with my, relatively, new Emag. I'm pretty sure that it's the Level 10 on mine......