the great 109 to 156 (using the new S-wing) and "lever" issues threads (continued)

[bj139]

I dove with the R109 yesterday on a pony bottle. Adjusted fully out there was a light freeflow (small leak) coming from the mouthpiece. Adjusting the knob in all the way stopped the flow but breathing was hard. Adjusting it out it breathed OK. I left it turned in and continued the dive. I later noticed bubbles trickling from the mouthpiece. Opening then closing the knob seemed to stop this. Today I bent the ears down more since there is no free play between the diaphragm and lever indicating to me the diaphragm is providing some preload on the lever opposite to the direction of the mainspring. If this preload is relieved it should allow the orifice to be adjusted out more without freeflow. Maybe I better check the orifice for dents with a magnifier to eliminate that as a possible problem. Are you sure these are the best regs ever made? They sure seem to be temperamental.

 

[NotSure]

I think if you could post some photos of your poppet, lever and spring the experts here might be able to help you. I don't find the 109 tempermental at all, they just don't work with bad parts like any regulator. Bending the lever is almost never the way to fix a lever height issue. From my very limited experience I think you are on the right track looking at the orifice. If you remove the diaphragm and bottom out the orifice and turn it out until the air starts to flow, how many turns does it take? I use the method I learned here and start by turning the orifice out 1 1/2 turns and if everything is working properly that usually gets you within a 1/4 turn of final adjustment. If the orifice and seat are good and you have the correct poppet you might want to check the spring length to make sure you have the right spring.

 

[Couv]

BJ,

One common mistake made is adjusting the orifice without depressing the purge button. If one does that, there is a good chance the seat will be engraved causing some of the issues you are describing. If the lever height is correct and the seat is good, I put my money on a bad orifice.

 

[bj139]

Couv,
I always depress the purge when adjusting the orifice, but this is good as a reminder. I took the reg completely apart to get the orifice out. I pushed it out with a wooden dowel. Under a magnifier, the orifice edge had a slight bump. It looked like a chrome plating imperfection. I used a Micro mesh stick for a few seconds only and smoothed it out. Breathing test seemed about as good as before. Sink testing showed no cracking up to mouthpiece level(2"), even when adjuster set near freeflow. It's like it does not crack cleanly but over a large range. Notsure suggested the spring may be wrong. The uncompressed spring length is 1 5/8" or 41 mm. Is this the correct spring for the unbalanced R109? The IP on the MK1 I am using returns to 121 after purge and climbs within 10 seconds to 125 where it is stable.
The Sea Hornet/Calypso combination I mentioned above cracks cleanly at 1".

I reread the post above by Zung about the three different levers. I have the one on the right. What is apparent from the picture is the leverage force exerted by the center lever is greater than the other two because of the foot height. If my spring is correct maybe my next step will be to try to turn my lever into #2 with a file (no pun intended).

 

[NotSure]

The 109 spring I measured recently was only 1.515" long. If your spring is 1.625" it could be part of your problem. It's probably the correct spring that someone stretched to try and compensate for a bad seat or orifice. At this point you need to throw that lever in the trash and find a new one. Bending a lever one way to solve a problem my be ok in some cases, but bending it back to it's original shape when you find the actual problem may cause it to become brittle due to metal fatigue. It's the angle of the feet on the lever that determine lever height, not the width. The width of the lever feet is only an issue if the feet catch on the poppet when you press the lever.

109 Spring Length

 

[bj139]

I compressed the spring as much as I could by hand and it reduced to about 1.55". I later compressed it in a vise with no change. This improved the cracking pressure to about 2". Thanks for the spring info NS.
I remembered when I first installed the G200 poppet there was binding between the lever feet and the poppet. I shaved a bit of the plastic poppet with a knife and eliminated the binding. The binding involved the height of the feet and the poppet and the air barrel. The higher feet were jamming the poppet against the top of the air barrel. The original one piece barrel poppet had no binding with this lever since it had more vertical clearance. I think the newer lever with shorter feet was meant for the newer poppets. I decided to file the feet to be shorter like the #2 picture in Zung's post above. The cracking pressure is now improved to 1.2". My first stage, an MK1 has an IP of 125 which is probably a bit low. Maybe increasing this would match the spring pressure better to the IP. Now I have to find out how to increase the IP on a piston first stage. Something about shims, I read once. Does anybody here know anything about this?
NS mentioned above the approximate orifice position is about 1-1/2 turns out. I am finding mine is 2-3/4 turns out. This would make sense considering the low IP.

 

[Couv]

Hello BJ,

(Skip to the bottom for the real deal.)

Yes, the first step should be to have a stable IP in the correct range. The MK 1 is basically a MK 5 with no swivel turret, so you can shim the spring with a MK 5 or MK 10 shims. The range is 135 +/- 10 psi or you can replace the seat with a shorter one.

Getting back to the second stage: I have five 109 springs that measure from 1.39-1.625 (~1 25/64ths inches to 1 5/8ths inches) if you PM me with your snail mail address I'll get a couple out to you and a couple of first stage shims. The only cost is to update this thread with your findings. BTW shaving a spring is an old school method of reducing the force it applies. (shim to raise-shave to lower.) If you choose to grind a spring, please ensure the end remains flat. Take it easy to avoid overheating the spring-a belt or disc sander with 80 grit or finer should work ok.

I didn't say this, and I'll deny it until I die, but you can also raise the IP by shaving the HP seat a little. If fact, if you look at a set of MK 10/5 seats you'll see that they are slightly different lengths to make adjusting IP as easy as replacing the seat.

Now for the real deal: The problem is probably a lever and poppet compatibility issue. A new style lever (#1 with the curly feet) and duro or s-wing poppet have always worked for me.

 

[redacted]

I didn't say this, and I'll deny it until I die, but you can also raise the IP by shaving the HP seat a little. If fact, if you look at a set of MK 10/5 seats you'll see that they are slightly different lengths to make adjusting IP as easy as replacing the seat.

Before you try shaving that HP seat, you can add a shim between the body and the seat retainer to get about 5 psi. Works really good on a Mk20 but you have to be careful with those older 1st that the added shim does not compromise the retainer o-ring seal at the base. At a minimum, it should give you an idea of what an increase in IP will do for you. I really can not imagine ithat small change making much difference in the 2nd stage orifice adjustment.

 

[bj139]

Couv, I think you are right about a lever and poppet compatibility. Above I show the problem I ran into when I installed the duro poppet. The poppet was jamming vertically between the air barrel hole, the lever foot and the top of the air barrel. I believe that is why later levers had much smaller feet. The original one piece poppet I took out was the barrel shaped one with a huge vertical space for the larger feet and had no such clearance problem. I then filed the feet smaller to give more clearance. The foot now looks close to the picture of the #2 lever. I will post some pictures of the poppet and lever the next time I take it apart. I want to see if I can see any roughness inside the air barrel that may be causing the poppet to hangup.

 

[Ed Palma]

Has anyone tried this purported SP tool from eBay ($35) to change the lever angle?

[h=1]Scubapro 109 Lever Height Tool with Instruction Sheet. New.[/h]



I read before that Awap had some success with bending the feet himself before. This might take the guess work out of that.

(both photos from the auction)