The song of a MK25

[Zung]

It goes like this... View attachment MK25-Song.zip (direct upload of mp3 not permitted, you'll have to open the zip file.)

This MK25 was serviced by a shop in Dec. 2009 and has about 40 dives since.
During the dive just before it started squeeling, there was a string of small bubbles coming out of the ambient chamber. I swapped in the spare reg and all was well.

More about it after the autopsy, meanwhile, what's your best quess?

1. Battery low
2. HP piston o-ring dead
3. Ignition too lean
4. Piston stem scratched
5. Karma
6. 

 

[axxel57]

Of course is the battery low, the tone should be much higher!

 

[lowviz]

longitudinal crack in the plastic tube?

---------- Post added November 24th, 2012 at 05:41 PM ----------

I don't know much about servicing regs, but I'm willing to play in the hope of learning something useful...

-given the choices, I'm going with 2. Final answer, 2.

 

[Pao]

Sounds like air leaking somewhere. Maybe an O-ring. Take it back for service .

 

[porbeagle]

Sounds like my MK V11
But I'll say #6

 

[chrpai]

That sounded like some kinky sh!t to me so I'll go for #6.

 

[Scubakevdm]

The ambient chamber bubbler is set too high. Seriously, and definitely not funny, if the tech was using a stainless pick to remove the oring sandwich from the body, they might have put a little scratch across that sealing surface. One other cause could be from the inversion of the bottom plastic bushing that makes up the bread in the oring sandwich, which has a smooth surface on one side and four dimples in the other. hopefully it's either the hp piston oring or the bushing, Good luck!

 

[redacted]

You could try packing the ambient chamber with K-Y jelly.

 

[halocline]

I'm not sure that's O2 compatible.

Anyhow, who cares why the thing whistles. The important question is, why can't FSU beat the stupid gators.

 

[Zung]

Ladies & Gentlemen,

The culprit is, of course, #2!
Here it is, in all its gory details:



Interestingly, there was no mistake from whoever did the service, the o-ring is the correct one with the painted on red stripe, and there's plenty of lube as you can see. I have no idea why it happened.

I put a PU 90 in, and all is well, no singing anymore.