Scubapro MK V versus MK 2 plus?

[Leicamshooter]

Would a late model Mark 5 1st stage still be a good choice over a Mark-2 plus? The type of diving it would be used for would be Southern California winter and summer diving (52. F water in winter). Occasionaly I might exceed 100 feet. The MK-2 plus would be new, but unbalanced. The MK5 is balanced, clean, but does have the funny metal yoke (3000 psi).

Your comments are greatley appreciated,
G Medina

 

[DA Aquamaster]

The Mk 5 is a great first stage and will give you performance that is virtually indistingishable from a Mk 25 in terms of perceived breathing performance at the second stage. The IP is stable and the flow rate is adequate to properly support and reward high performance second stages and it supplies more than enough air for any recreational diving need.

The thin 3000 psi yokes (with small diameter yoke screws) are not really well suited to 3000 psi use. The Mk 5 can however be easily upgraded to use the current Scubapro heavy yoke, the matte finish of the new yoke will however not really match the Mk 5's shiny chrome finish.

The Mk 5 came in three major flavors each with improvements that became more or less the industry standard during it's long production life.

The early ones had a thin 2250 psi yoke, a 2 port swivel cap, 1 3/8" HP port and large holes in the ambient chamber.

The next major variant was the same with the addition of a 4 port swivel cap and a thin 3000 psi yoke.

The late model Mk V's had a thick 3300 psi yoke using a large diameter yoke screw, two 7/16" HP ports, a 5 port swivel cap and (on the SPEC versions) small holes in the ambient chamber that were designed to retain environmental silicone in the chamber for reliable cold water use.

On a Mk 5 it is nice to have the current standard 2 HP ports, the heavy yoke and the 4 or 5 port swivel cap. With regard to the ambient chamber holes, the early production large holes are easier to rinse if you are not using silicone, which is commonly the case with users now that SP has moved away from using environmental silicone.

Parts are still readily available and the soft parts on the Mk 5 are still fully supported. Some of the hard parts are available as at times SP sees enough need to make a another production run on some parts. But the hard parts are also extremely durable and seldom need replacing.

I am not sure where you are getting your Mk 5, but I have three of them currently for sale, all have heavy 3300 psi shiny chrome, two are late production with two 7/16th ports and 5 port swivel caps (one has small holes in the ambient chamber and other has the smaller 1/16" SPEC kit holes) and one early production Mk 5 with the older 4 swivel cap and single 3/8th HP port and large ambient chamber holes.

 

[oxyhacker]

For a primary reg, I would take a decent used MkV over a brand new MkII anyday.

A used MKV with the skinny yoke is, however, not worth a whole lot - there are tons of good used MKVs around, so it makes a lot more sense to find one with the heavy yoke and maybe a 5 port turret, rather than buy one without and plan on upgrading it.

I've seen 3 yokes on them - the old, skinny one, a much beefier 3000 psi, and the late heavy one with the big bolt which may come in either shiny or matte chrome.

I've never seen a 3300 psi one, though - the late ones are usually not marked though most of the catalogs says they are rated for 3000 psi. Probably just SP being super conservative though, as usual, and I wouldn't hesitate to use either of the heavy variants with a 3442 psi tank.

 

[Wayward Son]

DA, do you happen to have any exhaust T's for the metal 2nd stage? I could use one for mine.

How much do you want for the Mk V's? heavier yoke version, I use some 3300psi 100AL tanks.

 

[DA Aquamaster]

I advised the new shop owner to stock up on some and I think he did so I should be able to get them. They are not quite like the originals as SP made a more generic tee that fits on both the O8O and 109/156 series.

I'd sell the single HP port/4 turret cap Mk 5 for $60 and the 2 HP port/5 LP port turret Mk 5's for $75 each. They are freshly serviced and ready to dive.

 

[Wayward Son]

I tried one of the current "universal T's" and they stick out too far from the body. Run into my chin. I can barely get the mouthpiece in my mouth, if I was wearing a hood it's be impossible. You might want to compare what he has with an original & see if it'll actually work. I still have my original but it could stand being replaced.

 

[redacted]

I tried one of the current "universal T's" and they stick out too far from the body. Run into my chin. I can barely get the mouthpiece in my mouth, if I was wearing a hood it's be impossible. You might want to compare what he has with an original & see if it'll actually work. I still have my original but it could stand being replaced.

I had to go look at mine and they definatly do stick out an extra 1/2 inch or so. In looking at the new T, I'm wondering if you could remove or reduce the vertical support piece at the inside center reshape the chin area by heating it, press that area in, and then storing it with something holding the new shape.

You might also ba able to find a mouthpiece that gives you a little more standoff. I believe the seacure mouthpiece is a bit longer. But I had trouble getting a seacure to seal on the R109. I ended up adding an O-ring to hold the seal.