SP s555 Vs G250

[Scubakevdm]

This must be a case of her regulator technician being better than yours. ;-)

Seriously, what would you attribute the smoother operation to? Are the innards (I like that word) i.e. the spring, poppet & lever different or is there something about the barrel design?

thanks,


couv

I think it's mostly the lever (which can actually make a big difference), but depending on when the last time the adjustable was serviced, the poppet may be different as well. Gas doesn't flow as smoothly past the original poppet.
As far as the OP's question... I'd go with the 250... either one.
I've noticed that some of the replies recommend a B2 over the SP G-250. I don't know... I have an ST1, it's okay... kinda wheezy. Maybe I just got a bad one. I also have a SP 650. I dove it three times and hung it up in some closet. I haven't seen it for a couple of years and really don't care where it went. It was very wet breathing, especially if you were inverted.

 

[redacted]

This must be a case of her regulator technician being better than yours. ;-)

Seriously, what would you attribute the smoother operation to? Are the innards (I like that word) i.e. the spring, poppet & lever different or is there something about the barrel design?

thanks,


couv

I think she may be sleeping with her regulator tech.:11:

Looking at the differences, it might be attributable to the lever design, the materials used in the diaphram (and its interface with the lever), and what amounts to a double balance chamber each of which may respond seperately. Also, the orifice and balance chamber adjustments may make the final adjustment a bit more sensetive. The final adjustement on the balance chamber seems to be easier to control small changes in cracking pressure than the orifice adjustement. Either that, or it is all in my mind. But it is nice to share air with her.

 

[Couv]

I think she may be sleeping with her regulator tech.:11:

Yikes, I hope her diaphragm is in good condition.

Looking at the differences, it might be attributable to the lever design, the materials used in the diaphram (and its interface with the lever), and what amounts to a double balance chamber each of which may respond seperately. Also, the orifice and balance chamber adjustments may make the final adjustment a bit more sensetive. The final adjustement on the balance chamber seems to be easier to control small changes in cracking pressure than the orifice adjustement. Either that, or it is all in my mind. But it is nice to share air with her.

After posting my lazy query, I got off my duff and had a look at a SP bulletin which gives directions how how to convert the G250 to the G250HP. In the bulletin the parts to be retained are the lever, spring and orifice. The discards are the barrel, adjustment knob, stop pin and balance chamber. The poppet assembly looks like the same S wing poppet, so it would seem, the major difference would have to be in the balance chamber. Of course, I do not know what the new barrel design is, as I have never seen one, but I'm sure there are modifications to allow the different type of balance chamber assembly and adjustment knob.

What I am not clear about is the lever, Scubakevdm mentions the lever design; however, the bulletin says retain the lever. Since it was published (#266 dated Dec. 15, 1999) has there been another upgrade?

One more question..is the G250 diaphragm the same/interchangeable as the BA?

Thank you,

couv

 

[volks_r_us]

<quote>next year in canada though, so a reg that doesn't freeze up too quickly (I won't dive in ice cold water..couldn't survive the idea) </quote>

All depends where you dive in Canada ?
If you go to Ontario ,St-lawrence River during Summer water is around 70s but is you Dive in a Lake you hit a first thermocline at 20ft. Water temps drop to 55 then at 60-80ft you hit a second and temp drop to the mid 40s. I you plan to dive in Quebec Let say the Empress of Irland water temps never get over 45

 

[halocline]

I can't imagine why anyone would want to convert a G250 to a G250HP. It's the metal air barrel on the original (and new G250V) that's considered a plus on the older G520s.

I have an old G250 and a metal case balanced adjustable on the same 1st stage, so it's easy for me to compare the two. If anything, the balanced adjustable is a little smoother, but it's a very small difference. The B/A is heavier, but with the right mouthpiece it's comfortable in the water.

 

[Couv]

I can't imagine why anyone would want to convert a G250 to a G250HP. It's the metal air barrel on the original (and new G250V) that's considered a plus on the older G520s.

I have an old G250 and a metal case balanced adjustable on the same 1st stage, so it's easy for me to compare the two. If anything, the balanced adjustable is a little smoother, but it's a very small difference. The B/A is heavier, but with the right mouthpiece it's comfortable in the water.

Mattboy,

I prefer the metal BA too. I have a couple of old G250ies that I will be selling as soon as I get parts to finish converting my metal non-balanced adjustable to BA.

From your comments, I guess that means that the HP has a plastic barrel, right? I noticed from the diagrams that there is a lot more monkey motion at the adjustment end too.

Also, still curious about the diaphragms in all of the above. Are they interchangeable? Has there been an upgrade to the lever since 2000?

couv

 

[Scubakevdm]

Mattboy,

I prefer the metal BA too. I have a couple of old G250ies that I will be selling as soon as I get parts to finish converting my metal non-balanced adjustable to BA.

From your comments, I guess that means that the HP has a plastic barrel, right? I noticed from the diagrams that there is a lot more monkey motion at the adjustment end too.

Also, still curious about the diaphragms in all of the above. Are they interchangeable? Has there been an upgrade to the lever since 2000?

couv

I'm pretty sure that the levers in the newer second stages are different, but I don't have an old BA to compare parts with. I think that the lever and poppet are not interchangeable, but are newer designs. If memory serves, the old poppet has a blue star shaped block for a stem. The new poppets are the white ones of an undescribable shape. I think that the difference on the lever is where it contacts the bearing plate of the diaphragm. I seem to remember a slight two stage cam action to the newer ones.

 

[Couv]

Scubakevdm,

You have a good memory. Yes, the old G250 and BA had the blue star shaped poppet with a metal stem but the new single piece s wing poppet replaces them. I just bought a few levers, and they seem to be the same as the old ones (my ba is 20 years old) But I do not know if I received "old stock" or if there is a special lever and diaphragm for the HP

I am at work in the stealth mode right now, so I can't go tear into anything. Even if I could, I do not have an HP to compare anything to.

thanks,

couv

 

[Scubakevdm]

Scubakevdm,

You have a good memory. Yes, the old G250 and BA had the blue star shaped poppet with a metal stem but the new single piece s wing poppet replaces them. I just bought a few levers, and they seem to be the same as the old ones (my ba is 20 years old) But I do not know if I received "old stock" or if there is a special lever and diaphragm for the HP

I am at work in the stealth mode right now, so I can't go tear into anything. Even if I could, I do not have an HP to compare anything to.

thanks,

couv

If there's a difference it would be at the points where it comes in contact with the diaphragm. They look like skates and the way that the lever rides off changes as it moves through the cycle.

 

[DA Aquamaster]

With some of the really old Adjustables you have to replace the lever with a new G250HP lever as the really old Adjustable levers bind on the newest version of the poppets used in the G250HP (s-wing) as well as the new poppets for the Adjustable and G200. So in short the new lever can be retrofitted into older Adjustables and BA's.