Mistral Mystery

[Bryan]

Our friend Scott Drennon has a very nice Mistral that does not seem to like me! (big surprise there) Originally it came to me for service / rebuild and everything came out fine as best I could tell. A few weeks later he let me know it was free flowing .... He sent it back, I polished the volcano orifice again, replaced the HP seat with another new one, new spring etc. All seemed good....Well it came back to me again with the same problem.....I can see nothing but normal wear on the HP seat, volcano orifice looks great and I cannot think of anything else to check/change or do differently. I put in a new seat and spring and the pressure is holding fine the past 2 days on the workbench.....Any suggestions of another avenue I should approach it from ? I want to remain on Scott's Xmas card list

[simonbeans]

Could the levers be a bit high so that the diaphram is making contact before inhalation?
By the way, Mike O was kind enough to send me a venturi nozzle for mine. Installed, ready to dive. Unfortunately, I owe him my first born, . . . .but maybe that isn't such a bad idea.

Thanks Mike O.
Allan

[pescador775]

Guessing there was bit of dirt in the HP block. If the orifice was out of round it would not have been repairable, at least not likely. You've done all you can.

[Nemrod]

I don't suppose anything has been done to modify that venturi nozzle.

I wonder if the return on the diaphram is weak?

See if the problemcontinues if you cover the venturi holes in the nozzle just as an experiment.

Nem

[Bryan]

It's like a new penny inside and there is no change in the venturi nozzle unless the people that did it restored the factory finish.......My eyes cannot detect any visible scratches in the volcano orifice but I gave it another polish with a hard felt bob that is shaped to fit both inside and out on the volcano.....Levers could have been a bit high but when you have them that way it usually leaks right off the bat.....I'll investigate a bit further....Thanks for the advice..

[captain]

USD or Spiro?

[Bryan]

USD.....If a Spiro was giving me this much of a fit you know it would already be in LaPlace....