I've Decided - MK25 EVO/S620 TI

[scubafanatic]

About 18 months ago I purchased a NIB MK25 EVO/S620Ti from a gentleman here on SB for $ 450 US. So far I've only pool dive tested it (practiced with it again yesterday in the pool) but it will be ocean tested in 2 weeks when I fly out to Costa Rica for a week-long live-aboard trip. So far it seems just fine!

 

[elbig]

Great price! I think you will be pleased.

 

[Blueringocto_73]

Pool tested the s620 Ti. Yeah it's going to do for me well into the future. The mouthpiece may get replaced later. It feels a bit small, but highly functional none the less.

Put the dust cap on the MK25 post dive and dunked it in the communal fresh water tank.

Read somewhere later: "don't "soak" the first stage reg. So it will only get a short fresh water rinse under the tap and then towel/air dried in the future. Don't want minerals or bacteria to congregate.

 

[stuartv]

Pool tested the s620 Ti. Yeah it's going to do for me well into the future. The mouthpiece may get replaced later. It feels a bit small, but highly functional none the less.

Put the dust cap on the MK25 post dive and dunked it in the communal fresh water tank.

Read somewhere later: "don't "soak" the first stage reg. So it will only get a short fresh water rinse under the tap and then towel/air dried in the future. Don't want minerals or bacteria to congregate.

I agree on the SP mouthpieces. I replaced all mine with Twin-Bite mouthpieces from DGX.

Twin-Bite Mouthpiece (6 Colors)

Much better (to me).

The Mk25 absolutely SHOULD get a good soak after diving in salt water. Ideally, in water with some movement. Having salt crystals build up inside the ambient chamber will contribute to needing to eventually replace the end cap (after many years). When I get home from a saltwater dive trip, I even put some Salt-Away in the water where I rinse/soak my regs. I also swish them around in there and then also aim running water into the ambient chamber holes to help flush the chamber out. Note that Salt-Away does not magically remove the salt. It just dissolves it so that it will wash away easily. You still have to rinse it well to get rid of the salt.

That is the one "knock" against unsealed 1st stages versus sealed. With a sealed reg, you can just give them a cursory rinse and let them dry. The unsealed regs need more soaking and rinsing, to get salt/silt/etc out of the innards.

I keep delrin caps on all my 1st stages, so I don't have to worry about getting water inside the reg when I'm rinsing/soaking.

DGX Threaded Dust Cap for DIN Regulator, Delrin

If you have a yoke 1st stage, I guess the SP dust cap is the best you can do, but I think they should really be fine, as long as you tighten the yoke enough, but not too much.

 

[Blueringocto_73]

Ha! Misspoke, I put the dust cap on the yoke. Yeah those mouthpieces look like good replacements. So I don't know why others are recommending not soaking the 1st stage reg. Could it degrade the seals early?

In your experience it's more important to remove the salts thoroughly than worry about the o-rings rotting from a soak.

 

[shurite7]

Ha! Misspoke, I put the dust cap on the yoke. Yeah those mouthpieces look like good replacements. So I don't know why others are recommending not soaking the 1st stage reg. Could it degrade the seals early?

In your experience it's more important to remove the salts thoroughly than worry about the o-rings rotting from a soak.

The main issue with soaking is the possibility of water leaking into the first stage. The dust cover which comes with a reg isn't always water tight. If you can, rinse the regulator in hot water thoroughly with a hose or under a faucet shortly after diving. Removing the purge cover to rinse the inside of the second stage is ideal, however, it is not recommend it unless you know what you are doing. If you can't rinse right away then soaking the reg for a little while may be a good idea. On boat dives I give the reg a rinse with bottled water just after the dive, then a thorough rinse when I get back.

 

[Compressor]

Another vote for SP regs. They are solid when taken care of and will last a lifetime. My set is from 1999 and works great. But I do service them regularly.

 

[Compressor]

Listen to StuartV. He gives on the spot advice.

 

[Blueringocto_73]

Thanks guys! Yeah I'm getting it now. Don't allow any water to get into the high pressure side from the yoke.

Thus make sure the original dust cap is replaced with another that seals better. And run very warm water from the tap over the 1st and 2nd stages as soon as possible.