My *new* old Scubapro 109

[ams511]

Thanks couv. I can't tell you guys how much I appreciate the help.

I did look down the barrel. Looked clean. Relubed the rings and reinstalled the parts. Spent much of the day and most of the gas in a small pony tank just playing with it, making small adjustments and following halocline's suggestion. Got it just past freeflow, put on the cover and it freeflowed. Frustrating. I know it's my lack of experience but I will get there.

I'm going to take a break while I wait on the lever and read Harlow again. Now that I have opened one up and played around with it some, I think it will make more sense. I also have an S600 that needs attention. I can start cleaning and inspecting it and that might give me a better understanding of these seconds but I don't want to move onto a first stage until I have a better grip on the seconds.

I am no expert but it the second stage does not free flow when the cover is off but does free flow when the cover is on I would suspect the level height. If the lever is too high then the cover will depress it and move the poppet away from the orifice which would cause a free flow or at least a hissing sound.

If you do not need your S-600 for a while you could remove the lever from it and use it on your 156. Just make sure you keep all the S-600 parts together in a bag or a container until the new lever arrives.

I have rebuilt first stages in the past and to me at least they seem easier than a second stage. To me the big battle is taking them apart as I did not have a good work area. I did a MK-2 first and when done I said to myself is that all. A Mk-5 was only a bit more difficult. A MK-25 looks intimidating on the schematic but if you follow the manual it is a piece of cake.

 

[halocline]

Spent much of the day and most of the gas in a small pony tank just playing with it, making small adjustments and following halocline's suggestion. Got it just past freeflow, put on the cover and it freeflowed.

This means that the lever is likely too high, which is what usually is the problem with the old lever and the new poppet. If you can adjust the freeflow out with the diaphragm in place by tightening the orifice 1/4 turn or so, fine, but any more and you are really hurting the performance of the reg.

Tightening the orifice does 2 things; it compresses the spring, which increases cracking effort, and it lowers the lever, by pushing the poppet back and thus changing the resting angle of the feet. You can see this quite easily with the diaphragm out. The idea behind herman's tool is to steepen the angle of the feet relative to the lever, so that at a given orifice position, the lever is lower, when viewed from the side without the diaphragm. Optimally what you want is for the lever to sit just at (or very slightly below) where the inside face of the diaphragm will be when the regulator is put together, at the orifice adjustment point where the reg is cracking at around .75 inch of water, i.e. just short of a light freeflow. The only way to get that perfect combination, if the lever doesn't have it, is to adjust the angle of the feet. This is definitely trial-and-hopefully-not-too-much-error territory.

When the lever is too high, and you have to lower it by tightening the orifice, you are increasing cracking effort un-necessarily. (I'm not sure if all that stuff is clear to you) But you also had a problem with free flow, which would be unrelated to this, so I'm not what's going on. Look on the bright side; you're learning, you're having fun, and you're spending WAY less than anyone walking into the dive shop and coming our with a plastic regulator in a fancy box!

 

[uncfnp]

Thanks halocline. I actually followed most of that. After I did the purge off/purge on test I would say to reliably stop free flow I needed a good 1/2 turn on the orifice. I also noticed that if I turned the adjustment knob in, consistence in purge response seemed to be greatly improved. With the knob fully open, free flow between tests was very inconsistent. So I put the knob at about a 1/2 turn in and this was where it was at when I tested it with replacing the purge cover but got the free flow. By this point my pony was pretty much empty so will experiment some more after I use couv's DYI equalizer to refill it.

Its odd that it seemed to work so well until disaster struck.

Yes. Frustrating but fascinating. The ignored chores are adding up though...

I pity you guys when I start the D400!

 

[halocline]

One thing about these 2nd stages is that they have a VERY powerful purge. In fact when I want to check 1st stage performance under stress I connect two 109s and an IP gauge to a single 1st stage and purge both 2nds at the same time.

Anyhow, the very powerful purge means a huge amount of air is flowing through the 2nd stage and that means a big venturi assist and likely free flow. If my 109s are adjusted correctly, and I press the purge, they will keep flowing ferociously until I cover the mouthpiece. That's normal. It can be pretty dramatic underwater, but if you cover the mouthpiece it should stop. Sometimes you have to stick your thumb in there.

I wonder if this could be at least some of the cause of your uncontrolled free flow.

 

[uncfnp]

I know I covered the mouthpiece and 50% sure I put a thumb in it. But there is a real chance that I just didn't address the freeflow aggressively enough. Still I am glad that I am going through this recheck and interested in seeing if the new lever makes any difference.

Busy with work and chores next few days but hoping to take the S600 apart and possibly try that lever.

 

[Couv]

....
If you do not need your S-600 for a while you could remove the lever from it and use it on your 156. Just make sure you keep all the S-600 parts together in a bag or a container until the new lever arrives.....

AMS, by chance have you confirmed the S-600 lever will work in a BA? I only ask because looking at the illustrated parts diagram, it seems like the lever for the s-600 is different than the one found in a G250/BA.

The poppet assembly and spring are the same part number, so I've no reason to believe it would not work unless the arms that interface with the diaphragm disc are of a different geometry.

UNCFNP, if you want to send me the old lever, I own one of Herman's lever adjusting tools. I'll be happy to check it for proper height and adjust it if necessary.

 

[redacted]

AMS, by chance have you confirmed the S-600 lever will work in a BA? I only ask because looking at the illustrated parts diagram, it seems like the lever for the s-600 is different than the one found in a G250/BA.

The poppet assembly and spring are the same part number, so I've no reason to believe it would not work unless the arms that interface with the diaphragm disc are of a different geometry.

UNCFNP, if you want to send me the old lever, I own one of Herman's lever adjusting tools. I'll be happy to check it for proper height and adjust it if necessary.

You can't really tell because lever p/ns change over time. But my 1997 schematics show a lever, p/n 11-109-105 in a BA/Ajd, a G250, and a G500. Since you won't find a schematic of the same date for a BA and an S600, you probably can't find those 2 listed with the same p/n for the lever, but we do know the G500 and the S600 are compatible so that lever from the S600 should be the most current lever for a BA.

 

[uncfnp]

I just took the s600 apart. OMG. I had read that there was little change in regs over the years but I couldn't believe how similar the 109 and the 600 are. Except for a few things, I felt like I was looking at a plastic version of my other regulator. Of course that is not really a fair comparison since I have modified the 109 and I guess it's now a 156?

And one of the slight changes is the lever.

Just saw awap's post. At least the lever is different from the one I ordered. I'll post pics if interested.

 

[halocline]

The more current lever, with the curved feet, is a bit shorter and the angles are a bit different than the older levers. I assume this is to better fit in the smaller S600 case. However, this is the lever that seems to work best in the 109s that I've converted to the s wing poppet. SP has a long history of updating parts and retro-fitting these parts into older regs. If you went to a dealer and ordered part 11-109-105, the part number for lever for the 109/156, the database would probably show that that part number has been replaced by 11-250-141, which pops up on schematics for the G250/G250HP/G250V. But the most recent parts list I have (2011) show a different number 11-600-141 for the S600, so maybe they are different. It wouldn't surprise me if the only one dealers can get is that latest part number, but I don't really know.

I do know that I have replaced the older, longer levers (square feet), with slightly shorter newer (curved feet) levers that do sit at a slightly more vertical angle when installed. It's always worked. I have an older G250 that has a square-foot lever as well, but that one came with the old style balanced poppet. I think that lever is still in there with a s-wing poppet.

I think the best performance comes from matching the lever to the poppet, not necessarily the reg model.