Saved a bunch of SP Mk5 / 109A regs from the trash :-)

[raftingtigger]

My dive buddy mentioned he had several old regulators that he was likely to trash. Turns out he had a SP MK7 with heavy yoke, 3 (or 4) MK5 (2 LP) 1sts, and 5 nice 109As with soft parts in good condition.

We are in the process of cleaning and overhauling them. Soon there will be another DIYer .

 

[redacted]

One thing your buddy should consider doing with his Mk7s is go ahead and breath them down from about 500 psi to below IP. The primary should be honking around 400 psi and will stop delivering usable breaths around IP when the oscillator stops working and blocks the outlet. No big deal as long as you know to go to the alternate when that happens.

 

[raftingtigger]

One thing your buddy should consider doing with his Mk7s is go ahead and breath them down from about 500 psi to below IP. The primary should be honking around 400 psi and will stop delivering usable breaths around IP when the oscillator stops working and blocks the outlet. No big deal as long as you know to go to the alternate when that happens.

I don't think he is planning on actually diving the MK7, but might use it as a source for a MK5 piston. We didn't take the 1st stages apart yet- he didn't have a vice - so we don't know the status other than they all have stable and appropriate IPs. Anyone know where 5 port turrets can be found?

 

[mjrob]

We all have vices. Some of us have vises as well. Let's not get into the virtues thing; I'll have nothing to contribute.

 

[halocline]

The only problem with trying to convert the older MK5s is that the yoke is very light and would need to be upgraded as well as the LP port turret. Some of the older 2 port turrets were held in place with a circlip instead of a bolt, and as such the later ones might not fit on the body, although I'm not sure about that.

It's going to be cheaper to just get later model MK5s than try to upgrade the 2LP port ones. But the heavy yoke MK7 is a winner and of course the 109s are truly excellent 2nd stages. If you get the right mouthpiece on one and convert it to balanced, IMO it's more enjoyable to use than any of the plastic 2nd stages.

 

[rx7diver]

... and of course the 109s are truly excellent 2nd stages. If you get the right mouthpiece on one and convert it to balanced, IMO it's more enjoyable to use than any of the plastic 2nd stages.

... except, maybe, the original G250 (with the SS barrel) and, almost certainly, the D400 and similar?

Safe Diving,

rx7diver

 

[halocline]

... except, maybe, the original G250 (with the SS barrel) and, almost certainly, the D400 and similar?

Safe Diving,

rx7diver

I have one G250 (an old one) one G200B, also old, and 6 or 7 converted 109s. I have not used either the G250 or G200B in several years, but I use the 109s all the time. They seem to have a more subdued venturi assist, which I like. I've bought and sold a few other G250s, but never kept any.

I also have several D300s which I do use occasionally. I used to use them all the time as primary 2nds until I got a couple of converted pilots, now I use those instead. There's something about the metal case that improves performance in a subjective way, almost certainly not measurable, but noticeable to a human diver. I have a theory (well, actually a wild guess) that the added mass in the case might provide a bit more smoothness in the air flow, and it definitely helps to warm and moisten the air a bit. These things end up mattering more over the course of a dive week than tiny differences in WOB as measured by a machine.

Scubapro really freakin blew it by discontinuing the center balanced valve, coaxial exhaust design of the air1 and D series. From an engineering standpoint those regs were extremely well thought out. But (another guess) idiot service techs couldn't stop complaining about how much it hurt their heads to actually learn something new, and poof...

 

[agilis]

I have one G250 (an old one) one G200B, also old, and 6 or 7 converted 109s. I have not used either the G250 or G200B in several years, but I use the 109s all the time. They seem to have a more subdued venturi assist, which I like. I've bought and sold a few other G250s, but never kept any.

I also have several D300s which I do use occasionally. I used to use them all the time as primary 2nds until I got a couple of converted pilots, now I use those instead. There's something about the metal case that improves performance in a subjective way, almost certainly not measurable, but noticeable to a human diver. I have a theory (well, actually a wild guess) that the added mass in the case might provide a bit more smoothness in the air flow, and it definitely helps to warm and moisten the air a bit. These things end up mattering more over the course of a dive week than tiny differences in WOB as measured by a machine.

Scubapro really freakin blew it by discontinuing the center balanced valve, coaxial exhaust design of the air1 and D series. From an engineering standpoint those regs were extremely well thought out. But (another guess) idiot service techs couldn't stop complaining about how much it hurt their heads to actually learn something new, and poof...

I have and use a D300 and a D350, and they are truly superb. When I picked them up they looked unused. One still had factory tags.

I have a small collection of 109 second stages, some upgraded, some not, (hardly any difference) including one I've owned since new in 1972. If I had a good step by step guide to working on D series regulators I'd use them more often. The 109s are a cinch, even a joy to work with, especially now that soft parts have become so readily available, but a schematic, all I have for the D series, does not provide enough information for me to feel comfortable. I hope to find a trustworthy competent specialist to eventually tune and replace soft parts on these two. I also have a couple of old 250 seconds that I seldom use, except for a 250 Graphite that for some reason is capable of being tuned so finely it is a pleasure to use.

Late model Mk5 and Mk10 firsts are so beautiful operationally and aesthetically that I use nothing else, except for a sealed Zeagle first stage that I use when diving in dirty/ sandy water. The 109 s and 250 s work perfectly with the Zeagle. Most of my firsts are converted to DIN or came that way originally, except for one Mk5 and one Mk10 that I use when traveling or renting tanks. If there were anything out there that was clearly functionally superior I would not hesitate buying it. Adjusting IP externally is not that big a deal.

 

[rx7diver]

... except for a 250 Graphite that for some reason is capable of being tuned so finely it is a pleasure to use.

Late model Mk5 and Mk10 firsts are so beautiful operationally and aesthetically that I use nothing else, except for a ...

Agilis,

I bought my G250 new in 1988. It's the Graphite version. I don't think I ever realized that there is an even earlier version. I just checked my old Scubapro catalogs and confirmed that, yes, the G250 that appears in the 1987 catalog does NOT have "Graphite" written on the purge button. Thanks.

In the early 1990's I converted two of my three Mk 10's (all three purchased 1987-1988) to Mk 10 Plus's. But my favorite SCUBA is the (plain) Mk 10 w/ D400 mounted on my steel 72 (original hydro 1970, purchased used a few years ago). Such a sublime package for the local freshwater, solo recreational diving I do these days (while wearing a 3/2 mm wetsuit and SS Freedom Plate).

Swapping out my D400 for my G250 nets a package almost as sublime. But, really, it's a toss-up between my G250 and my Balanced Adjustable. To me, the G250 breathes slightly, but noticeably, better, but the large exhaust tee on the Balanced Adjustable routes the exhaust bubbles away from my face better and, so, the Balanced Adjustable provides a more enjoyable scuba "experience."

Safe Diving,

rx7diver

---------- Post added November 15th, 2014 at 10:35 PM ----------

I have and use a D300 and a D350, and they are truly superb. When I picked them up they looked unused. One still had factory tags. ... but a schematic, all I have for the D series, does not provide enough information for me to feel comfortable. I hope to find a trustworthy competent specialist to eventually tune and replace soft parts on these two.

I trust my LDS to service both my D400 and my Air II. (I service my other Scubapro regs, myself.) The owner is a personal friend I've known for more than 25 years. He's been a Scubapro dealer all that time. If you cannot find a local tech, PM me and I'll forward to you my friend's contact info.

---------- Post added November 15th, 2014 at 10:40 PM ----------

I also have several D300s which I do use occasionally. I used to use them all the time as primary 2nds until I got a couple of converted pilots, now I use those instead. ...

Scubapro really freakin blew it by discontinuing the center balanced valve, coaxial exhaust design of the air1 and D series. From an engineering standpoint those regs were extremely well thought out. But (another guess) idiot service techs couldn't stop complaining about how much it hurt their heads to actually learn something new, and poof...

Halocline,

I hope I'll be able to try an Air 1 one of these days. And I agree: Scubapro should have continued manufacturing the D-series regulators!

Safe Diving,

rx7diver