Free flowing Mares abyss

[jf3193]

Good evening,
On my last trip to Bonaire, my Mares Abyss ( 10 years old but serviced by local shop annually) started to free flow at depth. I never could get it to correct itself on the dive, and switched to my pony bottle ( was headed back to shore already, so no biggy).
I did a few shallow dives after that, and it never acted up again. Has anyone else had an issue with a random free flow at depth? I’m curious to know if I should invest in a newer, more high end reg. ( paranoia).
Any thoughts /advice appreciated

 

[Scared Silly]

Just needs to be tuned. Start with checking the IP and go from there.

 

[jf3193]

Just needs to be tuned. Start with checking the IP and go from there.

I’m sure I’ll know this after answer, but what IP?
Internet protocol? ( joke)

 

[Cdncoldwater]

Intermediate pressure, pressure the 1st stage is set at, to deliver to your 2nd stage/octo. Most manufacturers are 125-155 psi.

 

[Scared Silly]

I’m sure I’ll know this after answer, but what IP?
Internet protocol? ( joke)

Checkout the sticky at the top of this forum: Regulator Inspection and Checklist (Rev-8)

 

[lowwall]

Can you give us more info? Which first stage do you have? Did you have two second stages, if so were they both freeflowing? What troubleshooting steps did you try (like blocking the mouthpiece with a finger)?

 

[Zef]

Good evening,
On my last trip to Bonaire, my Mares Abyss ( 10 years old but serviced by local shop annually) started to free flow at depth. I never could get it to correct itself on the dive, and switched to my pony bottle ( was headed back to shore already, so no biggy).
I did a few shallow dives after that, and it never acted up again. Has anyone else had an issue with a random free flow at depth? I’m curious to know if I should invest in a newer, more high end reg. ( paranoia).
Any thoughts /advice appreciated

Start your trouble shooting by check your IP...the MR22/Abyss 1st stage should be set between 142 PSI (9.8 bar) and 148 PSI (10.2 bar).

If you have a CWD (cold water diving system) installed then the IP should be set between 130 PSI (9 bar) and 136 PSI (9.4 bar).

-Z

 

[jf3193]

Can you give us more info? Which first stage do you have? Did you have two second stages, if so were they both freeflowing? What troubleshooting steps did you try (like blocking the mouthpiece with a finger)?

I don’t recall the 1st stage make. I know it’s a full Mares setup. 2 second stages ( both mares). The backup did not free flow. I did try to both block the mouthpiece and also tried to purge it , neither helped until i surfaced.

 

[Zef]

I don’t recall the 1st stage make. I know it’s a full Mares setup. 2 second stages ( both mares). The backup did not free flow. I did try to both block the mouthpiece and also tried to purge it , neither helped until i surfaced.

Could you snap and post a picture of your 1st stage?

Almost all the Mares diaphragm model 1st stages are set to the IP range I indicated in my previous post.

From the 2001 Mares service manual:

-Z

 

[rsingler]

If the backup didn't freeflow, that slightly decreases the chances that it was excessive 1st stage IP causing the freeflow. But most octos (not mine) are tuned more stiffly than the primary second stage, so it still could have been IP induced freeflow (too much input pressure for the valve setting).

But another possibility for an out-of-the-blue freeflow is the valve sticking open due to a mechanical factor. The first thing I'd do is disassemble the valve and look for a grain of coral stuck in the tiny crevice where the poppet goes into the balance chamber. That decreased clearance is one reason why some cavers prefer downstream (unbalanced) seconds: they're dirt simple, and there are only two moving parts: lever and poppet. Tuned properly (and regularly) they are perhaps more reliable than a balanced second stage when paired with a balanced first.