View Full Version : hissing and free flow on new flathead

08-12-2008, 10:31
bought my flathead vi in January and finally got to use it last weekend. when surfacing the reg free flowed, it stopped after breathing into it. today i hooked it up to investigate the see if there was a problem. with the predive lever all the way forward, sometimes it will free flow when hitting the purge, it does not do it with the predive lever off. it would stop if you breathed into it I also noticed a hiss that would come and go from the reg, normally stopping when you breathed into the reg or adjusted the resistance knob. is this normal or should i be sending it in for servicing?

thanks for the help

08-12-2008, 11:38
The freeflow when you purge with the pre-dive lever in dive is a sign of a well tuned reg. That it does not do it in the pre-dive position indicated that is working. The slight hiss suggests that it may be tuned a little too hot but as long as you can control it with a little turn of the adjustment knob, it should be fine. Or the tech can easily fix that with a slight adjustment.

08-12-2008, 11:47
I had the same issue with my wife's envoy when it was fresh out of the box. Even in the pre-dive state, it had a very slight freeflow. A slight adjustment with an allen wrench fixed it.

08-12-2008, 22:08
If you decide to give it a go yourself, there's a great thread in the "Fix It" forum here with detailed instructions from Larry and photos from a poster (of a Mares reg, but close enough for government work) that made the adjustment super easy for me; I had the same issue with an Envoy reg and think the flathead is very likely so similar that the instructions are relevant. Thread here: http://forum.scubatoys.com/how-do-i-fix/1240-wifes-envoy-freeflowing.html

08-12-2008, 22:39
Try just backing the adjustment screw back a tiny bit rather than having it all the way open.

08-14-2008, 07:30
My wifes octo envoy free flowed like that. We sent it back and had it adjusted.

08-14-2008, 08:02
the 2nd stage regulator is probably broke inside...

08-27-2008, 02:59
the 2nd stage regulator is probably broke inside...
why do you say that mine did the same thing out of the box but after working the adjustments a few time and a dive it works great.

08-27-2008, 10:00
the 2nd stage regulator is probably broke inside...

hardly seems like that's whats going on.
there is a link above with pictures on the adjustment... it was my first time messing with a regulator, and was simple enough to do... took no time to do it, i posted pictures... and the reg is perfectly fine. it's just a matter of detuning it a tiny bit (mine took like 1/6 of a turn or so)