How to restore a Scubapro Mark VII Honker

[happy-diver]

Can't describe this incredibly detailed invaluable thread, for honkers, honk honk!

 

[raftingtigger]

A Honker? You can pick one up on eBay for $40 on a good day.

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It was introduced around 1971

I can narrow that down for you quite a bit. When I bought mine in August of 1971 the design had been on the market for 6 months. My dad didn't like depending on new designs, but felt his 14-yo daughter was better off with a new design, rather than depending on the problematic J-valves. SPGs weren't really common or even affordable at the time.

FWIW, the 2nd stage I bought (109-A) at the same time is still my PRIMARY 2nd. I have a whole fleet of the 109-As, but my original is the one that is breathed from the most by far.

I tried over the years (in a pool) to see how long I could stand hearing the honker and the best I could ever do was just shy of 60 seconds. Part of my pre-dive checks was to 'test' the honker by just cracking the tank valve. Mine always started to honk when the SPG I had eventually gotten read between 500-600 psi.

When my somewhat inattentive son got certified at the age of 17, I got him a heavy yoke MKVII. He graduated to a non-paper weight (3-1/2# plus another 1# or so on port expanders) when I was convinced he was checking his gauges often enough. Actually, it only took one dive with him on the deep side of a steep drop-off to make the change.

 

[rsingler]

Terrific information! And a great story to boot!
Thank you, @raftingtigger

 

[Art Challacombe]

I’m reviving this old thread to thank rsingler for his tip on freezing stuck regulator parts. To start off, I just received a Mk7 that was in very poor condition. It was badly corroded and the piston retainer cap would not budge. There were three issues:

1) heavy corrosion;
2) under spring load and;
3) the pin holes were badly stripped by a previous owner or tech.

Even after a long soak in a vinegar and water solution, I had no luck with removing the cap. It was frozen solid. Usually, I would use heat and Kroil to loosen frozen parts, but using a propane torch in an area with several o-rings and a piston did not seem like a good idea.

I was about to give up when I remembered a post by rsingler where he put a stubborn part in the freezer for a day and then loosened it with much less effort. So, I decided to give it a try as I had nothing to loose. Into the freezer the Mk7 went.

The next day, I took the regulator out of the freezer and immediately put it in a vise. I managed to get enough bite on the cap holes with a Scubapro multi-tool and with some effort off it went. Rsingler’s tip worked!

The rest of the rebuild went smoothly without incident and now I have another Mk7 ready to dive. Thank you very much rsingler for sharing your expertise with us so that we can restore our beloved antiques.

 

[rsingler]

The credit goes to my wife, @Art Challacombe
She's the wizard food scientist who coaxed me against my better judgment into trying it.

Even old dogs can learn new tricks!