Anyone used a Scubapro MK5?

[captain]

Hey kityip i have a mark 5 scuba pro reg set for sale just serviced 2 weeks ago nitrox ready its almost brand new mabe used 30 times if you are interested let me know

I hope you aren't selling it to buy some thing made of plastic.

 

[lowridersvt]

lol there nice regs i was going to use them on my vintage doubles set up but im going to be using poseidons insted so i have these reg now and nothing to do with them lol

 

[FredT]

I bought my first MK V in 1972. I still have it in serviceable condition but have relegated it to fresh water use now, as it appears to be made of brass. There is not much chrome left on it after several thousand hours in seawater. I replaced it with an Oceanic piston first stage, as ALL the internal parts interchanged when they first came out, as did the parts to the Bouchat piston first and a few other "off brand" regs. BTW SP didn't come out with the Mk 10 until the patent ran out on the V. As soon as that happened the clones appeared and SP changed tack to the "improved" MK 10, Disastrous Mk 15, and it's OS recovery model the Mk 20. With the exception of the piston all Mk V "soft" parts can be had from non-diving related sources. The MK V is the easiest first there is to service with a couple "special purpose" tools that can be easily made by hand on a drill press. If you can get it back together with all the parts in it and it doesn't leak air where it isn't supposed to its right. It can actually be serviced on the back deck using 2 nails, a screwdriver and Q-tip. That was necessary after the last time I had one "professionally" serviced before Katrina. All regs went into a mail order "pro" after that storm because I just didn't have time to do them. I'm back to "self service" now.

FT

 

[halocline]

As soon as that happened the clones appeared and SP changed tack to the "improved" MK 10, Disastrous Mk 15, and it's OS recovery model the Mk 20. FT

Fred, what's disastrous about the MK15?

 

[FredT]

The first stage had a pilot rod that was almost symmetrical. Unless you looked really closely it was right easy to get it installed backward. When installed backward the reg would function for a while and then the first stage would lock shut.

This condition seemed to annoy the divers it happened to for some strange reason. This happened to a hunting buddy of mine at significant depth twice before they figured out what had happened. The reg was assembled backward at the factory! The internal design was changed, and all MK 15s were recalled to be "upgraded for free" to the MK20 design or they were "upgraded" at the next service interval.

After the decades of rock solid performance of the MK V/290 Adjustable combo the MK 15 almost single handedly blew the rep of SP line, although the original pilot valve O-ring carrier in the 400 series second stage pilot at about the same time helped that downward spiral along as well.

FT

 

[DA Aquamaster]

The first stage had a pilot rod that was almost symmetrical. Unless you looked really closely it was right easy to get it installed backward. When installed backward the reg would function for a while and then the first stage would lock shut.

There is no guide rod in a Mk 15 - it is a balanced piston design and the only moving part is the piston itself. I'd love to see the tech that could install the piston upside down - and then get it to work at all on top of that. I can't even think of anything in the Mk 15 that could be misconstrued as a "guide rod".

This condition seemed to annoy the divers it happened to for some strange reason. This happened to a hunting buddy of mine at significant depth twice before they figured out what had happened. The reg was assembled backward at the factory! The internal design was changed, and all MK 15s were recalled to be "upgraded for free" to the MK20 design or they were "upgraded" at the next service interval.

Ahh...I understand now...the famous "it happened to a buddy of mine" thing - the perfect starting sentence to any urban legend.

As an aside, there was no recall on the Mk 15 that ever resulted in them being upgraded/replaced with Mk 20's. They changed seats and seat carriers but those problems were resolved long before the Mk 20 came along.

After the decades of rock solid performance of the MK V/290 Adjustable combo the MK 15 almost single handedly blew the rep of SP line,

That would be decades of rock solid performance with both the Mk 5 and Mk 10. The "Adjustable" second stage was numbered R109 and it's balanced derivative, the "Balanced Adjustable" is numbered R156 in it's final iteration. The R290 was a euro version of the much more recent plastic cased R390.

The Mk 15 DID have problems, but they were related to the seat matrial that was used, the seat carrier/external IP adjustment, and service difficulty with the early bushing system used.

The concave seats used on the Mk 15 (as well as on the Mk 10 Plus of the same period) did not hold up well in service do to failures of the seat material that would lead to HP seat leaks resulting in IP creep. It took them a year or two to work out the material problems to make the concave seat design work in the Mk 15 and Mk 10 Plus and their rep did take a hit - although the later Mk 20 and Mk 25 owe much of their excellent performance to the concave seat design that Scubapro perfected.

The Mk 15 also used a seat retainer that was designed to allow external IP adjustment. The problem was that it was not up to the task of dealing with the same 300 bar (4350 psi) service pressures as the rest of the first stage and the original seat retainers were limited to 3300 psi service pressures until they could be replaced with more conventional non adjustable retainers at annual service (at no cost to the customer).

The Mk 15 used the same basic replaceable HP o-ring bushing design as the Mk 20 and Mk 25, but used a C-clip to retain the bushings inside the frst stage. This was extremely secure, but was difficult for techs to remove and replace unless they had suitable long reach snap ring pliers. This led to tech complaints about it being difficult to service and the bushings on the later Mk 20 and Mk 25 are retained with a spring that drops right out when the first stage is disassembled.

The Mk 15 also had the upper bushing permanently installed in the first stage body, while this bushing is replaceable on the mk 20 and Mk 25.

although the original pilot valve O-ring carrier in the 400 series second stage pilot at about the same time helped that downward spiral along as well.

I'm not sure what you mean by pilot valve o-ring carrier. The mid 1970's Pilot second stage used a pilot valve, but the D400 used a center balanced valve.

Around 1994 (after the Mk 15 problems had become history) SP did switch from the one piece brass aspirator body used in the D300, D350 and most D400 production to a two piece design using replaceable plastic orifice for what appears to be better economics for both company and customer in the event the orifice were damaged or the aspirator corroded. ($4.00 replacement cost versus $45) The problem was that the plastic orifce and it's duller, softer knife edge did not allow the same exceptional level of performance, which from SP's perspective did not matter as they were detuning it anyway to meet really stupid EU freeflow standards. A related isue was that SP was not bothering to train new techs in D400 tuning techniques which led to further service problems with the D400.

So in effect you are correct that SP hurt it's reputation by killing off the best second stage it ever made (in 2003), but for totally wrong reasons.

 

[stefusa]

DA Aquamaster, you should write a book about the SP line...
No kidding, always there for explanations about all the SP regs...

 

[ams511]

Does anyone know of a link that catagories all Scubapro products? I find their numbering system very confusing and difficult to understand.

 

[stefusa]

http://www.seastar.at/album/
I am doing it by looking at the pics..
Too bad, the text is..... not readable for me...

 

[ams511]

http://www.seastar.at/album/
I am doing it by looking at the pics..
Too bad, the text is..... not readable for me...

There are pages on the web you can use to translate foreign languages, such as Alta Vista. I am not sure of the language, where are .at domains from? Thanks for the link.