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ScubaPro D400/MK20

Discussion in 'Regulators' started by NickPhillips, Jul 4, 2012.

  1. NickPhillips

    NickPhillips Angel Fish

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    I traded some stuff through craigslist and got a bunch of stuff to include 2 scubapro D400/MK20 sets. I have never used scubapro stuff and wonder what your thoughts are on this 1st/2nd stage set ups. I know it is a bit old, my wife just got into scuba diving and will be her first set and I was hoping to o2 clean mine and throw it on a stage bottle. What are your thoughts? Also what is the 'dive' switch on the front.
     
  2. awap

    awap Solo Diver

    # of Dives: 1,000 - 2,499
    Location: Central TX
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    You may well end up moving the D400 to your primary regulator. The performance is that good. The lever on the front engages an additional spring that will increase breathing effort and reduce the initiation and severity of free flows when the regulator is not in your mouth.
     
  3. rhwestfall

    rhwestfall Orca

    # of Dives: 100 - 199
    Location: "La Grande Ile"
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    its one of the finest breathing regs ever made
     
  4. diveprof

    diveprof Regular of the Pub

    # of Dives:
    Location: Evans, GA (underwater of course)
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    I just posted in the ScubaPro forum asking them if they planned to made at D400V (answer is not at this time - short sighted folks that they seem to be). I get making the 250V, but for many the D400 was the premier reg. Then they made this 650 thing...I guess that they will make a square, heavy metal thing instead ....., oh, they did... You would think that they would listen to the"field" sometimes rather than just generating something "new" for "new" sake....
     
  5. smorneau

    smorneau Solo Diver

    # of Dives: 200 - 499
    Location: Maine
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    If you want to sell them let me know!
     
  6. diveprof

    diveprof Regular of the Pub

    # of Dives:
    Location: Evans, GA (underwater of course)
    1,780
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    Scubapro just doesn't get the demand for this reg
    If SP isn't willing to look at it. Perhaps Hog/Edge might pick up the banner and make a similiar reg.
     
  7. NickPhillips

    NickPhillips Angel Fish

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    I appreciate the reply's. Have any of you used the d400 with 50% or more o2? Any issues, recommendations
     
  8. nfarrar

    nfarrar Nassau Grouper

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    The G250v is easier to make and maintain. Thats why....
     
    awap likes this.
  9. diveprof

    diveprof Regular of the Pub

    # of Dives:
    Location: Evans, GA (underwater of course)
    1,780
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    I get that... I have a 250V too. However, when you look at the evolving scuba marketplace and the changes recently made by SP (ending the free part deal - yeah, I know there are mixed opinions about this subject but it was a great selling point for those who do service their regs yearly) the question becomes what separates SP from the rest of the marketplace. Selling a reg that looks and for the most part (at least when not in some mags "breathing machine") performs pretty much like many others (as far as a human is subjectively able to determine) is not the road to being able to maintain a premium price for the regs. A D400V would certainly be a departure from the "usual."
     
  10. halocline

    halocline Solo Diver

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    "A bit old"....these regs are newer than almost every reg that I use. A couple of issues with the MK20 are: 1) Find out if the recall on the yoke retainer has been done, if not you should get that done at some point. 2) If the piston is the middle generation MK20 brass-tipped piston, be prepared to get a MK25 piston as a replacement, usually about $60, and the reg will perform MUCH better over the long haul. For O2 use, the MK 20 would be fine I guess; SP makes a 'nitrox' kit for that reg that I imagine has a more O2-friendly seat and viton o-rings. That leaves only the bushings in the air path and I'm not sure what problem they would present. The D400 is a different story because you will never find the balance spool o-ring in viton, it's 4.5mm by 1 mm, and you will never find the seat in viton. I have no idea what, if any, impact that would have on using it for high percentage O2. IMO (which is hardly an authority on high percentage O2 use) a 109 might be a better choice for O2 use; there would be basically 2 o-rings and the seat in contact with the air, all of which could be found (or stamped) out of some fluoroelastomer. But I'm really guessing.

    As has been suggested, it's likely if you get the MK20/D400 in good tune you'll want to use it as your primary reg, nothing breathes better IMO outside of a pilot, and you'd have be a little nuts to use one of those as your primary.;)

    ---------- Post Merged at 06:45 PM ---------- Previous Post was at 06:39 PM ----------

    Unfortunately SP seems to be heading in the other direction and phasing out support for the D series other than rebuild kits. The pilot, air1 and D series do represent some very elegant engineering, and it's engineering that really does have an impact on performance for a change, not just something to impress breathing machines or include 'features' that sound good on the dive shop sales floor.

    I'm afraid that because conventional 2nd stages are already very good, far better than is necessary to enjoy diving, and because the vast majority of buyers will not be able to appreciate the subtlety of the D series design, there's little reason for anyone in the industry to return to it. SP did sort-of-pay-hommage to the D400 with the short lived X600, but it contained none of the real geometry and design advantages, it just sort of looked even uglier than did the D series.
     

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