mares mr22 2nd stage issue

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fathom13

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Location
Ogdensburg NY USA
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Hi all,
I'm new to posting on the board but have lurked for quite a while. I live on, and dive in the big old St.Lawrence river on the NY Canadian boarder. I've had my open water since 2004 and am just getting back into diving after about 7 yrs off (cpl kids and jobs) and would like to get my nitrox card. I just completed my wait for the huge number....21st dive!!!! and have run into a hitch with my 2nd stage.
I use a Mares MR22 abyss (as do both my partners) I really like the reg and had it overhauled in June.
Coming back to diving caused me to do a lot of reading on it, and I decided I wanted the 40 inch miflex hose routed under my arm to a 90 degree XS scuba fitting for the 2nd. I got the 1/2 to 3/8 adapter and put it on. I realize the dfc is supposedly meant for the other hose for the best flow, but most companies use 3/8 so I thought I would give it a try. The reg worked fine I dove it 6 times and it breathed just like normal and like my buddies, not that we are really pushing them at all anyways.
So, on my last dive I turned on my tank and heard kind of a little honk from the 2nd, then I breathed it and it felt different, harder to get a good breath, until you really sucked then you would get full blast. I breathed it for a minute or so and it seemed better so I dove it. Knowing my octo was working good I used the 2nd and monitored it, and it was different than before. After the dive I compared it to the other Abyss on site and mine was harder to crack, and had noticeable free play in the diaphram. the purge was also weak.
I got it to the shop and just like I thought would happen... I was basically accused of opening it up and messing with it. The tech said the adjustments were changed from where he set it, cause he logs the adjustments. I agreed with him that it was not the same but NO ONE opened the reg I can assure you I have enough hobbies to keep me busy, I dont want to learn how to tinker with my reg adjustments and drown myself!! He said the different hose and angle fitting were causing a bunch of hard breathing as well as the altered adjustment. which I disagreed with because I used it, and it was fine before the noise.
My questions are... can a 2nd stage come out of adjustment that quick on its own?
Could the different hose size and fitting cause some weird pressure or flow issue with the dfc port, and cause it to go out of tune?
thanks. :coffee:
 
Here were your "symptoms":

1. "It felt different, harder to get a good breath, until you really sucked then you would get full blast".
2. "Harder to crack, and had noticeable free play in the diaphragm. the purge was also weak".


These are typically lever height adjustment issues.

Your Abyss 2nd stage is an unbalanced, classic downstream design. The demand lever is held on by a nylock nut (a locknut). Demand lever height is a function of how far the nut is threaded on versus how deep the orifice is threaded into the air barrel... difficult to explain without a diagram, but adjusting a classic downstream is a balancing act between adjusting the orifice to achieve the lowest stable cracking effort, while adjusting the lever to the maximum height that does not "foul" the diaphragm and cause a leak or tendency to free flow...

And adjusting the orifice changes the lever height, so you need to compensate by adjusting the nut, and keep going back and forth until you achieve the proper "tuning".

It sounds to me that the nylock nut on the demand lever may have backed off. Small adjustments on this nut result in BIG changes in lever height. If the nut backed off a little, it would cause the lever to drop, and creates the symptoms you described.

Why would this happen? Defective nut, or improperly serviced??? I couldn't answer that.

Another, but kind of an unlikely possibility is if when you changed the hoses you did not use two wrenches when tightening the new hose fitting to the 2nd stage fitting, this could result in changing the "tuning" of your 2nd stage.

The orifice sits inside the second stage fitting that you attach the hose to, and it is remotely possible that if that fitting turned clockwise as you tightened the hose it would cause the lever to drop (and cracking pressure to increase as well!). So if a clockwise (tightening) twist of that fitting occurred, it has a double effect (both resulting in harder breathing).

It does not take much of a turn of the orifice to effect the performance of the 2nd stage, a turn from 12 o'clock to 3 o'clock would usually be quite noticeable, and could certainly happen if you got a little carried away tightening the hose and were not using a 2nd wrench.

Hopefully, whatever the cause was it is now "cured". I'm a happy MR22 / Abyss user, and find them very easy to service. It is my "go to" regulator.

Best wishes.
 
Last edited:
Lead addressed it well. I will add that there is no way that changing a hose can cause the issues you discribe. I would challenge the tech on "logging" his settings..IP (a pressure adjustment) sure but lever height....I doubt it, he may check a box that says he did but that means little.
As for the hose changing things, not going to happen. While the reg end connection of the hose may be bigger, odds are the internal diameter of the hose isn't and the second stage end for sure isn't. And even if it were, pretty much any first stage port is capable of flowing way more gas than any second stage can flow and any second stage is capable of flowing way more gas than any diver can actually breath so even if it were true, you could only tell at the upper end of the flow rates of the reg and need a machine to do so.
 
I can confirm that changing the fittings do not affect breathing, I have several dives on my mr22 since I changed to your config (40" hose with the 1/2"-3/8" adapter).. And im going to be diving with a 7' and expect no difference there either


Sent from my Nokia Lumia using Tapatalk
 
I was basically accused of opening it up and messing with it. The tech said the adjustments were changed from where he set it, cause he logs the adjustments..... I dont want to learn how to tinker with my reg adjustments and drown myself!!

My questions are... can a 2nd stage come out of adjustment that quick on its own?

No, you seem to prefer letting someone else tinker with your reg and drowning you!...

Just kidding, the fact that you had a reg problem and are here to tell the tale is yet another example of how regs are NOT life support, and if it fails you won't drown as long as you're diving safely. You had a mechanical problem, which is inevitable with mechanical devices sooner or later, and you switched to your back up, exactly as you were trained to do.

It's definitely possible that the lever locknut slipped, although that's not too common, or maybe on of the tabs on the lever bent or broke, also not common, or something happened with the spring. So the answer is yes, occasionally 2nd stages do come out of adjustment or otherwise stop working correctly on their own. Maybe the most common is if the spring is worn, and it's not replaced at service (usually they're not) it could break in use. I've seen them look okay and then break or almost break.

As far as the 'did you screw it up when you changed the hose' probably not, typically you can change hoses on a 2nd stage all day and you won't change the adjustment. You'd have to reach in the fitting on the 2nd stage and move the orifice adjustment to do that. You can, however, actually crack the case by manhandling the hose fitting; hence the use of two wrenches; one to remove the hose, the other to hold the fitting still.

Maybe you should re-think your avoidance of learning how to work on your reg, or at least find a new tech that's more competent and less accusatory.
 
If it is made by man, it can fail!!!:D
 
Thanks for the all the answers so quick.
I sure did used two wrenches to tighten the fitting. I figured it was some type of lever issue form the free play in the diaphram, I do know the schematics and how they basically function. I thought about getting into servicing them but I really have too many hobbies all ready, which is why I really got angry being accused of messing around with it. I'm not a moron or a liar, I have built multiple drag race engines, carburators, transmissions, rear ends, rifles, shotguns, and pistols. I'm sure if I wanted to mess with a reg I could learn how, and do it correctly. I just dont want to be bothered with something else to think about. I think my plan of attack will be just to keep it amicable with this guy, use him for air fills and odds and ends, cause he's close to me. But I will find a better place for service for sure.


thanks guys
 
So... to update if anyone cares. I had the same shop readjust the reg (I'm limited for options here). I was told that it was still hard to breath cause of the 3/8ths hose and 90 fitting and reducer, but the reg was all back to factory spec. If you read the first post you will remember I said it breathed just like the factory hose for the first 6 dives with the miflex. I checked for free flow by submerging it face down and it wouldnt crack before water was filling the mouth piece, another abyss flowed just past the zip tie. I changed it back to the original 1/2 hose and it breathed exactly the same as the miflex 3/8, 90, and reducer.
so needless to say I will be taking it across the bridge to Canada to have my work done. Also they said there was no paint on the screws when I brought it so someone must have touched it. Well.... when I took posession of it after the june service, I observed that there was no new paint on it and thought to myself "well they must not be paint dabbing them anymore"
I think they need a class on customer service, and integrity.
 
I would really hate to need to rely on a single LDS love living in central Florida have,at least 4 shops in a 10 mile dive and 20 or so between me and cave country. Find a new tech
 
So... to update if anyone cares. I had the same shop readjust the reg (I'm limited for options here). I was told that it was still hard to breath cause of the 3/8ths hose and 90 fitting and reducer, but the reg was all back to factory spec. If you read the first post you will remember I said it breathed just like the factory hose for the first 6 dives with the miflex. I checked for free flow by submerging it face down and it wouldnt crack before water was filling the mouth piece, another abyss flowed just past the zip tie. I changed it back to the original 1/2 hose and it breathed exactly the same as the miflex 3/8, 90, and reducer.
so needless to say I will be taking it across the bridge to Canada to have my work done. Also they said there was no paint on the screws when I brought it so someone must have touched it. Well.... when I took posession of it after the june service, I observed that there was no new paint on it and thought to myself "well they must not be paint dabbing them anymore"
I think they need a class on customer service, and integrity.

Every time I read a story like this, and it happens a lot, I thank my lucky stars that I work on my own regs, and there are people on this board that will help you.

It sounds like the guy working at the shop has little concern for your reg or understanding of how it works. In less time than it takes you to cross the bridge into Canada, you could probably fix this yourself. It's probably just a matter of taking the hose off, depressing the purge, and turning the orifice adjustment 1/8 of a turn counter clockwise, then re-attaching the hose and checking the cracking effort.

That said, I'm not a huge fan of the right angle fittings, but if you bought one that was designed for regulator use, I'm sure it has absolutely no effect on the cracking effort. I guess if it actually did restrict flow it could lower the overall performance of the 2nd stage, but not cracking effort.
 
https://www.shearwater.com/products/teric/

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