Micromag won’t fire

[oats944]

Hey guys, posted earlier about a missing Micromag sear pin and got that sorted. Thought I was out of the woods but not so much. Airs up fine, but nothing happens when pulling the trigger.

It’s a gen 2 Micromag with a Micromag RT/Retro valve. Valve pin is standard RT length. Factory single trigger frame. Sear is the wider/older style. Level 7 bolt. Credit card sized gap between trigger and sear rod. 800 psi output tank. Confirmed bolt slides into the breech. Bolt isn’t stuck to the bumper.

Trigger pushes the sear rod back as far as it will go in the trigger frame but doesn’t release the bolt. Trigger feels on the heavier/mushier side.

I slid the RT valve into a classic mag using the same asa/air line off the Micro and it works fine. Thinking it was a sear issue in the Micro I swapped the sear from the Classic into the Micro and still no shooty. Then I put the Classic valve in the Micro and it fired a couple times but then started leaking and was burping shots. Put the classic valve back in the classic mag and it works fine.

Any idears what could be the issue?

[superman]

i would bet on the sear being out of adjustment.

[nak81783]

On the Micromag, if you use a small tool to push the trigger rod back further, does it fire? If so, lengthen the trigger rod. I don't recall ever working on a Micromag, so I'm not sure if the credit card thickness gap applies.

Edit: Looks like superman beat me to it.

[oats944]

Thanks guys, I lengthened the rod until there’s no gap, and shortened it until there was a larger gap, still no dice. Back to a credit card thickness. I’m holding the trigger back with the grip panels off and the sear is as far back as it goes towards the back of the frame, still not firing

[Meglomachinist]

Check your on off valve pull it and lube the rings. I had this happen before when the bottom o ring gets slightly off. Pulled it apart popped the rings on right and gave it some oil and worked great.

[F1FX]

Have you tried increasing valve pressure (turn in velocity adjustment screw in)?

[oats944]

Thanks guys! I’ll try taking apart, lubing, and reassembling the on/off to see if that does something. I have tried adjusting the pressure with no difference.

What’s throwing me off is I put the valve with the same Asa and steel braided line in a classic Automag and it works just fine.

It’s got me thinking it has to be the something with the body. I put on a different trigger frame that I used to use on my Classic with no change. The trigger pull is a heavy squishy pull unlike any of my other mags. I’ll have to mess around with it more tomorrow.

[Kit352]

Have you tried tossing into a pond for a few days then bashing it against a tree? Usually frees things up nicely lol.

[BrickHaus]

I have this exact. Same. Issue. I have a gen 2 micro body, and a pro team benchy. I've tried both an X valve and a classic in it. Both valves work fine in other bodies, but I can get a single shot out of either valve in this body. I never get a bolt reset after that.

Albeit, I messed with this for about an hour, and that valve and body have been sitting since. i figured my sear was out of wack, but I made a few changes to no avial. Now reading this you got my brain thinking about that mag again.

[StaticShocked]

I have this exact same issue as both of you as well. I messed with it a few weeks ago but haven't done anything further. Gen2 Micromag, two different valve assemblies, both work in a regular body, neither work in the micromag. I have done the exact same troubleshooting steps at the op described to no avail. I will be intently watching this post to see if there are any ideas that I haven't tried yet.

[nak81783]

Do Micromags have a rail bushing? I get they don’t have a rail, but do they still require the bushing in the field strip screw hole? If they need it, and it’s missing, that could throw off spacing.

[oats944]

Hey guys, made some forward progress I think. So I bought the Micromag body/trigger frame and the Micro RT valve separately from different sellers. I also have a classic RT. I’ve been using an extra .750 RT pin I had laying around in the Micro and it’s not firing as mentioned above.

When I first got the Micro RT valve it leaked like crazy down the breech. I forget why I checked the pin that came with the Micro valve but it measured .725. That’s when I put in the .750 pin which stopped the leak, but it wouldn’t fire.

I tried dropping the pin from my classic RT which is shaved down to .742 into the Micro valve and same thing, won’t fire.

To see what happened when I put the .725 pin back in the Micro valve it leaked bad down the breach again but stops when I hold the trigger back. But I just found with the shorter .725 pin it does fire between letting the trigger go and pulling it back and holding it to stop the leak.

To be honest I’m not 100% sure of how pin length affects things, hoping someone can maybe respond to educate me some. But perhaps for an unknown reason this thing needs a pin somewhere between .742 and .725 where it won’t leak but will still fire? I only have one spare pin (the unmolested .750 one) which I’ll sacrifice by shaving down .001 at a time, testing it before shaving it down more, in an effort to end my misery. Hoping someone with more mag knowledge than myself could tell me if I’m on the right track first before I start that journey.

Thanks guys!

[StaticShocked]

Hmmm. I wonder if the centerline of the sear pivot pin is closer to the centerline of the valve assembly than on a AGD mag? I will check tonight. That would explain the shorter pin allowing it to fire. The .750 pin is long enough that it is actually closing the on/off when the sear is seated against the bolt, so the valve chamber does not have any pressure before the sear is dropped, then the bolt does not cycle when the sear is dropped because the spring is holding it back? That would explain how mine is acting. It acts like the on/off has pressure behind it but the bolt does not have pressure.

[nak81783]

oats944 Did you check for the bushing?

[oats944]

Ahh sorry I forgot to respond to you in that last post. Yes there is a bushing in the back hole of the grip frame.

[Meglomachinist]

I'm out of town this week on travel but can check my micro when I get home and see what pin length is in mine. It is also a gen2 and I've run both a classic and emag valve in mine with no issues. Will let you know Friday.

[oats944]

Ok awesome, thank you!

[nak81783]

Can you clarify how you “sorted out” the sear pin? AGD replacement part? Home brewed solution? Etc.?

Put the Classic on/off assembly in the RT valve, and try it in the Micromag. It’s a harder trigger pull, but I’m curious if you can get the same few shots and sputtering as you did with the entire Classic Valve assembly in the Micromag. I’m asking this to get info on the interaction of the larger Classic on/off pin lower diameter with the rear nub of the sear. I’m trying to determine if the smaller RT on/off pin lower diameter is missing the rear sear nub altogether.

[oats944]

The sear pin was home brew. I had a metal rod the same diameter as the larger part of the sear pin hole. I cut it to the right length and filed down the passenger side so it would fit into the tapered end and stay in place. Sear moves easily on it.

I put the classic on/off into the Micro valve. Leaked bad from the breach. I pulled the trigger back and it fired once and stopped leaking. Let go of the trigger and it leaks again. Pulled the trigger back and held it. No shots after the first one, but as I was holding the trigger back there was a small “pop” sound from the valve. Released the trigger, leak happened, pulled trigger and held, leak stopped, pop sound again, but that’s all that happened the couple times I tried it. Degassed and regassed and it was exactly the same with just the one shot after the first trigger pull.