Has SP stopped selling MK10+ Parts?

[divenutny]

Has Scuba Pro stopped selling MK 10+ Parts?

I recently bought a MK10+ w/G250 second hand. I tried the reg after the sale, it worked fine. Since I knew little about the reg, I brought it to a shop for annual servicing. The shop is telling me the 1st stage needs a new piston, that SP stopped selling them, that I need to buy a new 1st stage. I have not used this shop much in the past, but I feel they are reputable. The shop I had serviced my SP regs in the past has closed. I own a few SP regs. (MK5, MK 17). I felt using a MK10 for my pony would be a good choice, but I have not noticed any comments that SP stopped selling parts for their older regs. In fact, I thought that SP was the only company that offers upgrades for all their old regs.

I’ve seen folks selling MK10+ pistons on ebay. I have not tried to service a reg yet, maybe it’s time. I prefer to have someone that does this more frequently, service my regs.

Is anyone aware of SP not selling parts for older models? Where can I find info on which models they stopped supplying?

Does anyone know of a shop in the NY area that still has MK10+ parts and is willing to service a Mk10+ reg?

Thanks - Tom

 

[LeadTurn_SD]

You may want to send a PM to DA Aquamaster and ask. He may eventually see this thread and respond.

Best wishes.

 

[halocline]

I also see NOS MK10+ pistons from time to time, but much more commonly see MK10 pistons. If you can then find a seat retainer for the MK 10 you could convert your MK10+ back to a normal MK10 and you'll probably have better lock up, by which I mean more stable IP.

But, you can probably clean up your current piston and resurface the edge, which should dramatically cut down on the IP creep. I'm assuming the reason your shop told you it needed a new piston was because they put a new seat in and it creeped. Feel free to show this thread to them. Maybe you'll get an unusually good tech who is interested and skilled enough to work on the piston.

There's a good thread in the "repairing your own gear" forum about this very process, started by Zung. He had a couple of creeping Mk10+s, resurfaced the pistons, and they work like new. It takes patience, some good abrasive cloth like micromesh (emory cloth would probably work), and a magnifying glass to really inspect it carefully.

I'd be surprised if DA Aquamaster would agree to working on the piston in that way, but he might have access to a NOS MK10+ piston or the parts to convert it back to a MK10, and he's certainly one of the best SP experts around. He hasn't been around the forum in a while.

 

[divenutny]

mattboy, thanks for the info. I have no issue rebuilding the reg to be a plain mk10. I will be asking around once I get the reg back.

As you thought, the tech replaced the seats and is still noticing some IP creep. I looked at the piston, he did not see any marks. He was confident a new piston would solve it.

Although I have rebuild a few car engines, I'm hesitant to rebuild a regulator. That might change if I cant find a shop to install a new piston. I read the thread about this. Sounds like fun.

This is the first I have heard SP not providing parts for older regs. Have you heard anything about that? I guess I need to surf a bit more to learn more about this.

 

[BlueWaterDiving]

When I was at the last ScubaPro clinic. They said they were bring back and making the
MK10+ piston and kit so that you could make your MK10 a MK10+. Please do not ask me why. I like the old MK 10 much better.

 

[Jax]

What is the difference between a 'plain' MK10 and an MK10+?

 

[redacted]

A Mk10+ uses the same seat as is used in a Mk20/25. Requires a different seat retainer and a piston with a somewhat blunt edge. It presses against the seat material rather than cutting into it.

The Mk10 uses a hard nylon seat that is cut by the sharp knife edge piston.

 

[Zung]

mattboy's said it all.

If you've worked on a car engine, you have more than enough skills to do reg's, but you may have to invest a hundred bucks or two in special tools: Scubapro multi-tools, bullet, IP gauge, all available from scubatools.com., plus 1 or 2 torque wrenches, 35 in.-lbs and 22 ft.-lbs.

If you want to do it the "official" way, there's a NOS MK10+ piston here. A much better way is to polish the tip like mattboy said; afterward, you've got a like new piston.

 

[oly5050user]

Has Scuba Pro stopped selling MK 10+ Parts?

I recently bought a MK10+ w/G250 second hand. I tried the reg after the sale, it worked fine. Since I knew little about the reg, I brought it to a shop for annual servicing. The shop is telling me the 1st stage needs a new piston, that SP stopped selling them, that I need to buy a new 1st stage. I have not used this shop much in the past, but I feel they are reputable. The shop I had serviced my SP regs in the past has closed. I own a few SP regs. (MK5, MK 17). I felt using a MK10 for my pony would be a good choice, but I have not noticed any comments that SP stopped selling parts for their older regs. In fact, I thought that SP was the only company that offers upgrades for all their old regs.

I’ve seen folks selling MK10+ pistons on ebay. I have not tried to service a reg yet, maybe it’s time. I prefer to have someone that does this more frequently, service my regs.

Is anyone aware of SP not selling parts for older models? Where can I find info on which models they stopped supplying?

Does anyone know of a shop in the NY area that still has MK10+ parts and is willing to service a Mk10+ reg?

Thanks - Tom

What LDS did you take it to? Maybe I can help as the facility I teach out of is a SP dealer.I just checked with our tech that works on regulators every day and he says to bring it in,parts ARE available!We are in Westchester NY almost on the NYC border line.

 

[halocline]

As you thought, the tech replaced the seats and is still noticing some IP creep. I looked at the piston, he did not see any marks.

That's because he didn't look at it with a 10X or stronger jeweler's loupe. I'm pretty confident you'll see a landscape of marks if you do that.

You have to understand the forces at work here. The piston edge must seal against a plastic seat, holding back 3000 PSI of pressure. IP creep is a very slight leak of that HP air past the piston edge, into the stem, and up into the IP chamber of the reg. The edge is being forced against the seat with relatively low pressure, about 130 PSI minus whatever the spring is pushing, so maybe a total of 40 lbs or so of pressure. (That's a guess) The MK10 has a sharp edge that cuts into the seat; that means very little surface area of contact between the piston and seat, so more pressure on the edge itself. The MK10+ has a blunt edge and a much larger area of contact with the seat. That means less pressure, more finicky when it comes to absolute air tight sealing. The advantage, at least in the MK20/25 which uses the same type of piston, is that the seats last forever, where the MK10 seats (at least mine) have to be replaced fairly frequently or they'll start to creep, maybe within 100 dives or so. It really depends.

The other advantage of the rounded piston is that it theoretically increases the efficiency of air flow around the piston edge. The MK10+ does have higher flow rates. Not that it matters, a MK10 will easily drive several 2nd stages at any depth at which a sane person would dive.

Nobody really knows why the MK10+ had such a 'creepy' reputation, whereas the MK25 is rock solid. Awap has a theory that's it's at least partially due to the smaller piston head diameter of the MK10, which results in proportionally less force acting on the edge. That makes sense to me, and I bet he's right. I also suspect that the piston edge design went through enough modifications so that by the time the MK25 came around they really had it right.

If, as Red says, SP is re-introducing the MK10+ conversion kits, maybe we'll get lucky and they'll upgrade the original MK10+ piston so that it's edge is identical to the current MK25 composite piston. If that's the case, it's worth buying. If I could buy a rounded piston that worked like the MK25 I'd buy one for each of my MK10s.