There have been a lot of MR12s. Most of them use a simple basic downstream where the lever height can be adjusted by pulling off the cover and diaprhagm then (to detune) slightly loosening (turn counter-clockwise) the little lever nut to lower the lever.
However when you do this you aren't really detuning the reg, you are just lowering the lever. This will be beneficial if it's too high, but won't do anything if it wasn't but except reduce the regs output.
This is where, with the Mares, it gets complicated. On a typical two-adjustment 2nd basic downstream there's a second adjustment, an adjustable orifice, which can be screwed in or out to increase poppet spring pressure and hence cracking pressure. However, even though many of the Mares 2nds have adjustable orifices, Mares doesn't seem to want them used this way, and says to adjust the cracking pressure by diddling with the intermediate pressure. This requires an IP to gauge to be sure you don't go too far, and probably not something a beginner should be doing casually.
You really ought to get someone who knows how to do it to show you, or get some more detailed instructions (like say, a book) rather than trying to do it one the basis of a brief post on the net.
Also, keep in mind that there are freeflows and there are free flows. Many modern high performance regs have a tendency to freeflow at certain times - it's an unavoidable price we pay for them being easy breathers the rest of the time. If the freeflow can be stopped by simply covering the mouthpiece, or giving a quick puff of air into it, then you maybe better living with it. Also, if your 2nd has a venturi boost adjustment, that adjustment will effect how liable it is to freeflow.
zboss once bubbled...
Hey -
I have heard that regulators are very easy to field adjust for free flow problems. Keeping that in mind I have been told that my new Mares MR12 has a tendancy to do so... so - if I intend on diving it regularly (which I do) I would like to know how to adjust the reg... can someone point me in the right direction?
Thanks...
