Old ScubaPro R109 2nd stage

[redacted]

I flipped the seat in the newer one, but it looked like it had some adhesive on it before. Or was that just gook from the seat under pressure?

Some techs used a little rubber cement to stick them in place. It does not adhere very well and can usually just be rubbed off of both the seat and the poppet.

Unless you plan to go beyond recreational nitrox (40%), O2 cleaning is unnecessary.

 

[Texfrazer]

I hadn't considered doing my own O2 cleaning. Is that easy/safe?

Unless you plan to go beyond recreational nitrox (40%), O2 cleaning is unnecessary.

Also, if you decide to go higher than typical nitrox (or you decide to mix your own), O2 cleaning is relatively easy and safe. Before you venture into that arena, you will want to pick up oxyhacker's book.

 

[aquaregia]

Vance Harlow's OXYGEN HACKER'S COMPANION From AIrspeed Press ?

 

[aquaregia]

So I pulled them apart, cleaned them and tried to put them back together. The poppet is slipping past the lever after reassembly if the lever moves too far up (closed, I guess). If I hit the purge button a few times, it slips past (loudly), and I have to disassemble and reassemble. The lever doesn't look particularly bent or anything.
This is the 109 that worked fine before I took it apart.

 

[redacted]

The poppet will only go in one way and engage the lever correctly. Sounds like yours may be in wrong. The "feet" that engage the lever must face the back of the case (same direction as the mouthpiece). I install the lever first. The I hold the lever as far up as it will go and install the poppet. Use something soft like a plastic pen to push the poppet towards the orifice while holding the lever up. The poppet will pull the lever down to the operating position as it seats. If you leave your pusher in place and lower the lever, you should see the pusher move about 1 mm. push the pusher and the lever will rise again to the operating position. I rarely remove the lever unless I need to do some heavy cleaning. Once the adjustment knob is removed and the spring & cap (or balance chamber are dumper out; I use the soft plastic ink cartridge from a ball point point to remove the poppet. Simply hold the lever as far up as it will go and insert the plastic cartridge through the orifice and just a little force should push the poppet out.

BTW, I have to figure out the correct orientation of the poppet each time I assemble one. Luckily, I had a 109 disassembled in a plastic bag that I could look at to write this.

 

[aquaregia]

The pen did the trick. I was lining it up before I dropped it in, but I think it didn't fall in straight. I applied a bit of pressure as I jiggled it putting it in, and it seems to be okay. Now to find my tiny allen keys...

 

[Texfrazer]

BTW, I have to figure out the correct orientation of the poppet each time I assemble one. Luckily, I had a 109 disassembled in a plastic bag that I could look at to write this.

And I thought I was the only one that had to do this!

And yes, aquaregia, your link to Vance's book is the correct one to use.

 

[aquaregia]

Ugh, I can't get the other one in now. Do you guys do it with the orifice in or out?

 

[redacted]

Ugh, I can't get the other one in now. Do you guys do it with the orifice in or out?

Orifice installed to limit poppet travel. I screw the orifice all the way in and then back it out 3 or 4 turns. I want it to leak when first pressurized.

BTW, I ran into a new downside of using the -010 with a metal orifice. I had a hell of a time removing an orifice that had been installed with a -010 quite a few years ago. This was in an old beater 109 that only saw FW use. I decided to test the Trident seat in it so I converted it to Balanced Adjustable. The orifice was a bit tight and after clearing the threads, I could not get it to push out. I lubed the surface of the barrel and used the pencil reaser to avoid damaging the knife edge but it just did not want to come out. Once I finally got it, I replaced the -010 (I could tell by the color) with a -902 and it installed quite easily. Maybe the -010 is a bad idea even if it does fit.

 

[aquaregia]

Just for closure, I dropped by a mate's place and we tuned the 109s to 1.2" and 1.5", with the Mk10 (guess I was wrong about it being a Mk5) to 137psi. Replaced the poppet in the older one with the newer style and did the exhaust valve, plus a bunch of the o-rings. 1st stage took a shim, and it still drifts a little, but seems okay. Haven't gotten in the water with them yet, but I'm excited for it.