MK17 or 25 on a S600

[radsman]

It seems I typically see the MK17 paired the with the G250V and the MK25 with the s600. Is there a reason for this? Has anyone had any experience with a MK17/S600 setup?

While I primarily dive in temperate waters, I recently moved to CO and may start diving in colder waters and lakes. Between the two, sounds like the MK17 is the way to go. Don't think there would be much difference b/w the G250V and S600 in cold water and I like the s600. Or would it be better to stick with the MK17/G250V?

Thoughts?

 

[SangP]

The s600 is mostly a plastic 2nd stage where as the g250v has a metal barrel. Personally I would go for the g250v as it does breath a bit more moist than my previous s600.

Stick with the mk17/g250v.

SangP

 

[c5diver]

both my kids dive mk 17/s600s in michigan, no problems. as mentioned the s600 is plastic but still works well.

 

[DA Aquamaster]

THe G250V has a metal air barrel extending all the way through the case. Attached to it is a large splined metal nut on the inlet fitting side and and a splined metal adjustment knob on the other end. Those pieces create significnat surface area to improve heat transfer that in turn keeps the air barrel inside the reg a lot warmer, reducing the potential for the second stage to freeze and freeflow.

Second stage freeze ups basically never occurred with metal cases, but they are much more common with plastic cased second stages and in particular with a plastic case and plastic air barrel like the S600. Go with the G250V if you are diving cold water.

 

[kathydee]

.....

 

[a22shady]

As the others have stated the G250V is a better reg for the colder water's and when its coupled with the MK17 it's an awesome reg for any water temps, Great breathing performance. My G/F actually has had her S600/G250V hooked to both the MK17/25 and noticed no difference. Since then she feels safer diving with the MK17 as it is sealed and here in the Northeast we dont have warm waters. Since using both she feels the G250V is actually a better breather then the S600 but likes the Smaller size of the 600. Either way she uses MK17/G250Vprimary and the S600 as her Back-up.

I also use the Scubapro MK17/G250V as well as an Atomic M1 set

 

[divin'dog]

My votes for the MK17. I have it and love it. Being sealed makes it all that much better esp in NE.

 

[halocline]

It seems I typically see the MK17 paired the with the G250V and the MK25 with the s600. Is there a reason for this?

I think it's a mostly marketing decision. In fact, re-introducing the G250 was probably a marketing decision as well, SP probably got tired of seeing old G250s sell for over $100 (just the 2nd stage) on ebay. The A700, I suspect, started out as an idea to re-introduce and "update" the fabulously successful balanced/adjustable 2nd stage. I'm very curious to see what they look like inside, although I do know they do not use the same poppet as the G250/balanced adjustable.

Hey SP, when are we getting a new MK5?

 

[DA Aquamaster]

I think it's a mostly marketing decision. In fact, re-introducing the G250 was probably a marketing decision as well, SP probably got tired of seeing old G250s sell for over $100 (just the 2nd stage) on ebay. The A700, I suspect, started out as an idea to re-introduce and "update" the fabulously successful balanced/adjustable 2nd stage. I'm very curious to see what they look like inside, although I do know they do not use the same poppet as the G250/balanced adjustable.

Hey SP, when are we getting a new MK5?

I have not disected one in detail, but from what I have seen taking one apart, it incorporates the best features of a few different regulators:

1. the all metal case of the R109/R156,
2. the basic well proven balanced poppet technology used in the G250-S600, and
3. the coaxial adjustable flow vane of the X650.

The result should be very good performance but with smoother airflow than the S600.

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I'd love to see a "new" balanced piston design similar to the older Mk 10. The Mk 25 is too large, too heavy, offers too much performance (of no value to a diver) with inadequate coldwater protection. And while the bushings in the Mk 25 make annual service easy, it ups the parts count and some of the gee whiz features like the adjustable IP seat retainer, just create more potential for leaks and failures.

If SP would re-introduce the Mk 10 (perhaps with an *optional* christolube filled ambient chamber along the lines of the old SPEC system) they'd sell a bunch of them. Good Mk 10's are becoming rare and a "Mk 10V" would provide the same solid Mk 10 performance and reliability in a smaller, lighter, simpler first stage.