ScubaPro Mark 7 service question

[tboydva]

I'm new to this site - but wanted to thank you folks for links to the service kits! I have two MK7-109 regs (I bought them in the early 80's). I was an avid diver (a lifetime ago), but haven't done much lately. One kid will get certified this winter so it was time to dust off the collection. It's probably a liability issue (hosting info on regulator servicing), but are there any resources for DIY service/repair. I used to work part-time in a dive shop and did regulator servicing - but this was over 20 years ago. I assume I'd get the hang of it again, but might need a little hand-holding in the beginning.

I seem to remember replacing the poppet in my 190 with a balanced one (if that's the term). I think this was in the late 80's. Would that have been possible? Perhaps I'm remembering incorrectly?

Anyway, thanks again for the links!

 

[rhwestfall]

I'm new to this site - but wanted to thank you folks for links to the service kits! I have two MK7-109 regs (I bought them in the early 80's). I was an avid diver (a lifetime ago), but haven't done much lately. One kid will get certified this winter so it was time to dust off the collection. It's probably a liability issue (hosting info on regulator servicing), but are there any resources for DIY service/repair. I used to work part-time in a dive shop and did regulator servicing - but this was over 20 years ago. I assume I'd get the hang of it again, but might need a little hand-holding in the beginning.

I seem to remember replacing the poppet in my 190 with a balanced one (if that's the term). I think this was in the late 80's. Would that have been possible? Perhaps I'm remembering incorrectly?

Anyway, thanks again for the links!

take a look (and maybe post) in the DIY forum. There are a bunch of folks and information there to assist you.

 

[DA Aquamaster]

The Adjustable (109) to Balanced Adjustable (156) conversion was very commonly done back in the day and still is.

 

[tboydva]

Folks, thanks for the rapid replies... Sorry about not searching first. I was so excited to see parts kits for my old (but comfortable) regs that I just let my stream of consciousness get the better of me. My LDS gave me the song and dance about the regs being obsolete and unserviceable. I ordered the DIY book found through one of the links in the DIY forum. That should be enough to get my memory working. I'm supposed to be doing some oceanographic survey work off Palawan Island in the the Philippines this Fall... I want my gear ready to go!

Thanks again.

 

[tboydva]

Sorry to drag up an old thread, but I have a question relative to the first post here. I got my kits and rebuilt my MK7 regs (and got an extra 1st stage from ebay). All three are adjusted for IP and work great - except they don't appear to honk anymore? The first post mentions an "audio alarm adjustment." I have parts diagrams, but no service manual for the MK7. In my part-time stint working at a shop (in the 80s), I'm sure I serviced these regs (even my own), but I don't recall making adjustments for the alarm. That was a long time ago, though. Can anyone help me with the adjustment?

Thanks!

 

[redacted]

It takes a fairy strong draw of air to make it honk. That is, if you are a sipper there may be little to no honk. My Mk7s (3 of them) all honk in the 350 to 400 psi range. I have never seen a service manual but see nothing in the design that suggests the honking is meant to be adjustable. That said, I'm sure you could shim the spring on the stem and have some effect.

 

[tboydva]

Thanks for the rapid reply... Mine always used to honk when I turned off the air and pushed the purge valve on the 2nd stage (when it got down to less than ~500 psi). I thought maybe it needed to be wet, so I submerged it. Took one to Mexico last month and dove with it. Still didn't hear the honk when removing it from the tank... Maybe as you suggest, the new o-rings and rebuild makes a stronger draw necessary to invoke the honk. Otherwise, all of them work great. I enjoy underwater photography, and I love the way the extra weight of the MK7 "floats" me. Another thanks to all in this thread!

 

[redacted]

Mine will fail to honk in that situation (draining residual pressure) more often than they will honk. I believe the air flow at the right pressure is so little that the necessary oscillation may not occur. You might try it again with the valve not completely shut down. Better yet, try it with a tank between 400 and 500 psi.

 

[Couv]

......and make sure you're hooked up to the correct port. (don't ask how I know)