Poseidon Cyklon 5000 vs. Jetstream

[Fossil_Diver]

If you had to choose one which one would you choose and why?
The reason I ask is because I have one of each and I'm trying to decide which one to keep.
I'm leaning towards the Cyklon because the second stage is a more familiar design to me and I have managed to service mine and reassemble it without using any special tools. It's a little tricky putting the diaphragm assembly together without the special jig but once I figured out the trick it's actually pretty easy. But the diaphragms seem delicate compared to most other regs. I have already noticed special care needs to be taken to the exhaust diaphragm post dive to get it clean and free of debris so it seals correctly. It sure ain't no Sherwood Brut. It came with the omni swivel and I can use hoses other than Poseidon with it. I have it routed under my arm and it is really comfortable that way.
I don't really like the sensitivity switch on the Jetstream because I already had to repair a leak on mine and it just seems to be a potential failure point. Also the upstream valve is unfamiliar to me and it looks like some parts may be difficult to source or be $$$. But the diaphragms seems more robust than the Cyklon ones. It doesnt have a swivel and it looks like I am stuck using Poseidon hoses or installing an overpressure fitting on the first stage.
I am looking at the regs at this time soley based on the ease of DIY maintenance. What I would like are other opinions on maintenance/servicability and also on performance for different environments. Is one better for cold water or deep diving, etc.
Thanks!

 

[tbone1004]

no problems sourcing any parts for the jetstream these days. Poseidon USA is doing a great job to prevent that from happening.

Jetstream omni-swivel has an OPV built into it if you buy the nice one and also adapts to a regular hose, but if you have the 3790 style first stage it has an OPV built into the first stage so no problems there.

I dive Jetstreams exclusively and wouldn't switch to anything but the Xstreams personally. They are just two completely different regs and you have to pick one or the other if they are on the same first stage due to IP, if diving with separate first stages, then you can easily use one of each.

 

[Fossil_Diver]

I believe my Cyklon first stage is a 3585 with the banjo fitting for the high pressure hose. Does anyone know what the M7 threaded port is just above the banjo fitting is for?
I think the Jetstream first stage is a 2962 without the built in overpressure valve.
I have seen the swivel for the Jetstream but I hate paying $80 for a fitting. Call me cheap but it is what it is lol.

 

[tbone1004]

I hear you, they aren't cheap, but thankfully the Jetstream can at least be used with any first stage if you want to upgrade and OPV's are cheap as are the non OPV adapters from DGX.

It all depends on what you want out of the regulators, I much prefer the dive-predive switch on my Jetstreams for DPV diving, but the Cyklons are super nice as well so for me it owuld all come down to whichever you felt breathed nicer

 

[Fossil_Diver]

@tbone1004 have you had the opportunity to dive both types with those first stages on them? It feels like the Jetstream breathes a little stiffer than the Cyklon but I haven't had a chance to go deep with it yet. It's my understanding that deep diving is where it performs better compared to the Cyklon. Or is it thr other way around? But how deep is deep? I don't plan on going deeper than 140' and most my diving is shallow water fossil hunting and metal detecting.

 

[Fossil_Diver]

This is a tough decision to make. It's like trying to choose between a Mustang or a Camaro.

 

[tbone1004]

it depends on how well they are tuned....

Are you sure the first stages are different other than one being yoke and the other DIN? First stage shouldn't matter that much as long as the IP is tuned appropriately for the second stage. The Cyklon wants 165psi, the Jetstream wants 123psi.

 

[Fossil_Diver]

They are both DIN with yoke adapters. They both have the truncated? ends. One is not flat on one end like the 3790.
The Cyklon one has one R port for the reg, three lp ports and an S port for a drysuit. And also has that weird metric m7 port that is blocked off just above the hp port.
The Jetstream has one R port and three lp ports.

 

[Fossil_Diver]

Other than the number of ports I think internally they are the same. The only difference is a restrictor screw in the 3585 first stage for the Cyklone. I think it is used to limit the ip to one or more of the lp ports. I think the R port gets the 165psi and maybe the S port or one or more of the lp ports are restricted to 123psi? Still not quite sure though.

 

[Fossil_Diver]

I can't find any info on the .pdf about how the restrictor screw is adjusted or what it is for or what the M7 port is for. The port shares the same chamber as the hp port. They are right next to each other and when I shine a light in the hp port I can see it in the M7 port.