Scubapro balanced adjustable second stage freeflowing

[MarkH]

That’s an ebay thing (in my experience) — I was able to reach out to a couple sellers outside ebay and things were much more reasonable
(Ebay even double charged me when getting tiny stuff from the same person)

Ok, back on topic. One more shot in the dark (even tho unlikely as you said the lever when touched prompted freeflow)
Is there any play in the lever motion (rotationally, basically in the direction it should move in) or “abrupt” clicking when you breathe from the reg?

I just wanna make sure the poppet leg isn’t stuck between the lever feet and the orifice
This happened to me on the 1st g250v I got used and only noticed it in water (when pressing the purge did nothing)

I'm not sure what you mean by "play" in the lever motion. Depending on how the Orifice is adjusted, there could be lots of play or none (when the lever is at max height). The rectangular holes in the barrel that the lever feet go through seem ok. They don't seem like they have any uneven wear. I never got it breathable enough to see if there's a click just before cracking, but my 109 does that sometimes (not really a click, but more like an abrupt cracking) when it's adjusted a certain way (not after final adjustment). I ordered some "curly feet" levers that are supposed to correct for this. Another strange thing I noticed and I don't know if this is normal or not, is that when I pressed in on the end of the adjusting knob, or wiggled the knob, the air leak would sometimes get better or worse. I assume this is due to small play in the threads. I imagine that due to the way the poppet "floats" a bit loose in the barrel, it doesn't take much side loading to break the seal at the seat.

 

[MarkH]

So, because of my stubbornness, I've ordered (from various places) a new lever (curly foot), orifice (plastic) and a G250 second stage repair kit (including S wing poppet). The only item that I couldn't find anywhere is a new spring. The places that have it listed on their websites said they don't sell them to the public, but only use them for in-house servicing (which is strange that they would list them for sale on their websites). There was a spring for sale on E-bay as the right one based on the part #, but the picture showed it was the larger unbalanced spring. There was no packaging so who knows what you're really getting online.

 

[scrane]

The ebay guy is a retired technician. He probably knows what he's talking about. Send him a message and ask.

 

[Mobulai]

I'm not sure what you mean by "play" in the lever motion. Depending on how the Orifice is adjusted, there could be lots of play or none (when the lever is at max height). The rectangular holes in the barrel that the lever feet go through seem ok. They don't seem like they have any uneven wear. I never got it breathable enough to see if there's a click just before cracking, but my 109 does that sometimes (not really a click, but more like an abrupt cracking) when it's adjusted a certain way (not after final adjustment). I ordered some "curly feet" levers that are supposed to correct for this. Another strange thing I noticed and I don't know if this is normal or not, is that when I pressed in on the end of the adjusting knob, or wiggled the knob, the air leak would sometimes get better or worse. I assume this is due to small play in the threads. I imagine that due to the way the poppet "floats" a bit loose in the barrel, it doesn't take much side loading to break the seal at the seat.

No I was referring to the full slippage of the poppet beyond the lever feet
Kinda like so:

Basically the lever drops so hard, but when the knob is threaded in all the way it rises again to a minimal(ly insufficient) height

Beyond the one time I saw it in a g250, I actively fought this issue with the old levers on the 109/BAs that I had to install an takeout the poppt multiple times till it engaged properly

 

[MarkH]

No I was referring to the full slippage of the poppet beyond the lever feet
Kinda like so:
View attachment 916083

Basically the lever drops so hard, but when the knob is threaded in all the way it rises again to a minimal(ly insufficient) height

Beyond the one time I saw it in a g250, I actively fought this issue with the old levers on the 109/BAs that I had to install an takeout the poppt multiple times till it engaged properly

I can't see what's going on inside the barrel, but I assume something as mismatched as your photo would be obvious (I hope). I think it would feel and sound a bit nasty to force the poppet past the feet like that although in the past I admit I've accidentally installed the poppet on my 109 upsidedown and I think that happened. For something to do today, I tried assembling and setting up my problematic balanced adjustable again. I got it so I could get it to stop leaking by with the adjustment knob about 1/2 way screwed in. I have a 2" H2O vacuum gauge so I rigged it up to measure cracking vacuum and it was around 1", which I assume is ok. I'm still going to try rebuilding it again when all the new components I ordered come in in a couple of weeks, but since the manual (at least for the balanced G250 versions) says to do the adjustments of the orifice with the adjustment knob backed out all the way, my new question is for users of these adjustable regs (109, balanced adjustable, G250, etc.), where do you usually set your adjustment knobs? I assumed you set the lever height to just barely not hissing by with the adjustment knob all the way out or maybe even hissing by a little bit and then screw in the knob maybe 1/2 turn until it stops.

 

[Nemrod]

I'm still going to try rebuilding it again when all the new components I ordered come in in a couple of weeks, but since the manual (at least for the balanced G250 versions) says to do the adjustments of the orifice with the adjustment knob backed out all the way, my new question is for users of these adjustable regs (109, balanced adjustable, G250, etc.), where do you usually set your adjustment knobs?

Mark, I would set customer regs such that after the seat had indented they would be in the middle of the cracking effort range from the SM. At least that was always my intent. My personal regs I set such that with the knob fully out there is a very slight, almost inaudible leakage. I then have to turn the knob inward 1/2 to 1 turn max to stop the leakage. This does a couple of things:

1. When I need air (like when I go into afib ) I can get all I need with no effort
2. This acts somewhat as a seat saver reducing seat pressure on the orifice when fully backed out.

My opinion, you need a new seat and a new orifice.

Sounds like you might be making progress, check your assembly order in particular as pointed out with the feet to poppet interface.

 

[Mobulai]

I can't see what's going on inside the barrel, but I assume something as mismatched as your photo would be obvious (I hope). I think it would feel and sound a bit nasty to force the poppet past the feet like that although in the past I admit I've accidentally installed the poppet on my 109 upsidedown and I think that happened. For something to do today, I tried assembling and setting up my problematic balanced adjustable again. I got it so I could get it to stop leaking by with the adjustment knob about 1/2 way screwed in. I have a 2" H2O vacuum gauge so I rigged it up to measure cracking vacuum and it was around 1", which I assume is ok. I'm still going to try rebuilding it again when all the new components I ordered come in in a couple of weeks, but since the manual (at least for the balanced G250 versions) says to do the adjustments of the orifice with the adjustment knob backed out all the way, my new question is for users of these adjustable regs (109, balanced adjustable, G250, etc.), where do you usually set your adjustment knobs? I assumed you set the lever height to just barely not hissing by with the adjustment knob all the way out or maybe even hissing by a little bit and then screw in the knob maybe 1/2 turn until it stops.

Well yes I present an excessive situation, but that’s why the curly lever is the one recommended for the new thinner Swing poppet, so it doesn’t collapse and slip

Again, I was just asking on the off chance just to cover all bases

 

[halocline]

It seems like this is an almost dangerously quirky reg engineering-wise compared to other ones I've worked on…..but with this one, if something is just slightly out of spec, to the point of me not even being able to visually see it, the reg will fail and maybe kill me 100' deep. If I can find a single source of parts, I might still give it a try out of stubbornness.

I couldn’t disagree more, and I’ve worked on dozens of these things. I use them for my 2nd stages in cave diving exclusively, even though I’ve had much more modern 2nd stages and I could use anything I want. These things are as reliable as it gets.

As an aside, no regulator is going to ‘kill you’ at a 100 feet or any other depth. Regulator failure is a nuisance, not a danger, if you’re diving safely.

Getting back to your problem, I don’t know if you’ve tried a new spring, but several people have suggested it and my experience is that changing the spring on these 2nd stages (as with the G250/200B) tends to make them much easier to tune. But, what you’ve described is pretty unusual, it goes way beyond normal tuning issues, assuming that I am accurately understanding your description.

It’s possible there’s an issue with the balance chamber; there were balance chambers of differing lengths and I would get a new one. When I convert a 109 to balanced, I change all the parts in the valve mechanism; spring, poppet, balance chamber, and then I closely inspect the orifice with a loupe and make sure the surface is pristine.

Another thing you could try is to get the duro poppet, and leave it unbalanced, using one of the larger springs. They perform quite well unbalanced; they might not hold a tune as long or as accurately, but with a good 1st stage it’s only a subtle difference between the unbalanced and balanced poppets in a 109.

Trying it with an unbalanced poppet would eliminate any question about the fit of the balance chamber. Another thing to try is to confirm that your orifice is in fact the correct length; I’ve seen a brass orifice that for whatever reason, was a different length and tuning the reg with it was a nightmare. Eventually I figured it out; I think someone had substituted that orifice for a OEM at some point earlier in the reg’s life.

Once you get it working without a diaphragm in place, then you can start looking at the lever height. That’s the one area that I have found finicky with these 2nd stages, but usually it only results in slight variances in how low you can get the cracking effort with the diaphragm in place.

Good luck, if you decide to throw in the towel, I’d be happy to take it off your hands and try to get it working just for fun. If I have success, I’ll be happy to send it back or buy it for a reasonable price, or trade something. I don’t really need any more of these, that’s for sure!

 

[MarkH]

I couldn’t disagree more, and I’ve worked on dozens of these things. I use them for my 2nd stages in cave diving exclusively, even though I’ve had much more modern 2nd stages and I could use anything I want. These things are as reliable as it gets.

As an aside, no regulator is going to ‘kill you’ at a 100 feet or any other depth. Regulator failure is a nuisance, not a danger, if you’re diving safely.

Getting back to your problem, I don’t know if you’ve tried a new spring, but several people have suggested it and my experience is that changing the spring on these 2nd stages (as with the G250/200B) tends to make them much easier to tune. But, what you’ve described is pretty unusual, it goes way beyond normal tuning issues, assuming that I am accurately understanding your description.

It’s possible there’s an issue with the balance chamber; there were balance chambers of differing lengths and I would get a new one. When I convert a 109 to balanced, I change all the parts in the valve mechanism; spring, poppet, balance chamber, and then I closely inspect the orifice with a loupe and make sure the surface is pristine.

Another thing you could try is to get the duro poppet, and leave it unbalanced, using one of the larger springs. They perform quite well unbalanced; they might not hold a tune as long or as accurately, but with a good 1st stage it’s only a subtle difference between the unbalanced and balanced poppets in a 109.

Trying it with an unbalanced poppet would eliminate any question about the fit of the balance chamber. Another thing to try is to confirm that your orifice is in fact the correct length; I’ve seen a brass orifice that for whatever reason, was a different length and tuning the reg with it was a nightmare. Eventually I figured it out; I think someone had substituted that orifice for a OEM at some point earlier in the reg’s life.

Once you get it working without a diaphragm in place, then you can start looking at the lever height. That’s the one area that I have found finicky with these 2nd stages, but usually it only results in slight variances in how low you can get the cracking effort with the diaphragm in place.

Good luck, if you decide to throw in the towel, I’d be happy to take it off your hands and try to get it working just for fun. If I have success, I’ll be happy to send it back or buy it for a reasonable price, or trade something. I don’t really need any more of these, that’s for sure!

I was sort of joking and being over dramatic about the reg killing me. I've just never had these issues before with all the other regs I've rebuilt before. They all went smoothly. If this one does decide to suddenly freeflow at 100' because the spring is 1/2mm too short or there is a microscopic nick in the orifice or the lever feet aren't 100% straight, then I always carry a 30 cuft bailout bottle with an unbalanced MK5/109 on it. I'm still waiting for all the parts I ordered to try rebuilding it again. When they all come in in a couple of weeks I'll update. The parts I couldn't find anywhere on the internet are the spring and the balance chamber (I did find the balance chamber listed on some of those European supply places, but they want something like a $50 minimum order and $50 shipping or something like that). I think the spring looks and measures fine and the balance chamber holds pressure and "springs back" with the S wing poppet so I think they're ok.

 

[Nemrod]

think the spring looks and measures fine and the balance chamber holds pressure and "springs back" with the S wing poppet so I think they're ok.

The S wing poppet with the dual O-rings will work with the older, shorter, balance chamber. The purpose of the outer O-ring is to provide a lubrication seal of the area between the two O-rings to extend service interval. You will not get that benefit.