Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: pop off valve

  1. #1
    is that a popoff valve on top of the clean out if so who carrys them??? http://free.***

  2. #2
    How can you see anything past that scoop?

  3. #3
    jim lee
    Wow that boat sure does look kinda' familliar..
    Yes, that is a popoff valve. They are made by Dan Nelson. I belive he's from Phoenix AZ. Or at least near there. Used to drive/own the blown gas jet "Jett Bayou". He's now the crewchief for Jim Sampica's Blown gas jet.
    Sorry, I did have his Phone # at one time, but I' can't find it now.
    -jim lee

  4. #4
    Yes thats a pop off valve and I have no idea who makes them. But you might want to give Jack at MPD a call I bet he could find one for you!

  5. #5
    I have a brand new one, it even has an air bottle to reset it $1600.00 Jim (818)890-1867

  6. #6
    An Air Bottle?? The guys at the races were saying that after they stopped they actually had to get a tool and reset it. Now I'm not the smartest man in the world but doesn't anyone here think that possibly a Pop Off vale triggered by Manifold Vaccuum would work about 500 times better??
    If manifold vacuum goes beyond X amount the pop off valve releases letting any extra bowl pressure out. When the Manifold reaches under X amount of vaccuum or possitive pressure (blown applications) it reseats and seals. God Dam I should've been an engineer particularly for the marine industry. Between switching the prop to the front of the outdrive and this I could be a rich man!
    JetBoatGuru, you writing this down I think I just came up with the next product!!

  7. #7
    Do you think 10Lbs manifold pressure in a carb boat can reset 120Lbs pump pressure, when you let off in a jet the intake pressure almost doubles, you need co2 to have enough pressue to rest it. Jim

  8. #8
    What is the purpose of the pop off valve??

  9. #9
    Senior Member
    Join Date
    Feb 2009
    The pop-off valve is a safety device. If there were to be an engine failure resulting in the jet pump shaft stopping spinning, a large, rapid pressure buildup would occur in the pump intake assembly. This would cause the rear of the boat to rise forcing the bow down. The result could be a very serious accident. The most common safety device is the jet-away or ratchet which allows the pump shaft to continue to spin as the boat slows. The jet-away is a purely mechanical device. The Pop-off is triggered electrically and can react much faster than the ratchet. Water from the pump intake housing is dumped through the opening on the back of the valve. It can also be triggered by a driver control switch. This allows for a safer decel after a run.

  10. #10
    Yea, my Dad crashed his dragboat years ago for that very reason. Shoe depth was set too deep to load the pump. When he lifted after the pass, the pump pressure was too great caused the boat to re-enter so violently, it disentigrated upon impact. (300 lb 19' kevlar tunnel) Those were the days before pop-offs.

Page 1 of 2 12 LastLast

Similar Threads

  1. pop-off valve
    By plj/fry in forum Jet Boats
    Replies: 33
    Last Post: 07-19-2007, 07:37 PM
  2. Replies: 5
    Last Post: 06-11-2007, 03:20 PM
  3. What is the PCV valve for?
    By Statue in forum Jet Boats
    Replies: 9
    Last Post: 05-19-2006, 09:30 AM
  4. T-valve
    By blown428fe in forum Jet Boats
    Replies: 14
    Last Post: 04-24-2006, 10:42 AM
  5. Gate valve or Globe valve?
    By lakecrazy in forum Jet Boats
    Replies: 10
    Last Post: 01-07-2003, 07:55 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts