Daystate Harrier Valve spring strength

Discussion in 'Daystate' started by ratty, Jul 12, 2018.

  1. ratty

    ratty Member

    Joined:
    Apr 19, 2013
    Messages:
    40
    Location:
    Rotherham
    Club:
    Anston
    Hi
    I recently removed a failling reg from my harrier and am trying to set it back up without the reg .
    All was going well got 767-780 fps nice i thought then as the air pressure lowerered in the cylinder the fps would creap up every shot until !!!.

    Ive assumed that this is due to the valve spring not having enough strength and the air pressure is whats closing the valve hence as the pressure drops fps goes up as the valve is open longer .

    To save me lots of trial and error would anyone know what the normal valve spring pressure required to open the valve is or any comparisons with other non reged rifles?

    Cheers Dave
     
  2. cloverleaf

    cloverleaf Active Member

    Joined:
    Sep 12, 2014
    Messages:
    311
    Location:
    Oxfordshire
    We all know what assumption does ;)

    Your problem sounds a lot more like the reg pressure set too high; the muzzle energy creeping up once the gun comes off-reg and the pressure to which the valve is exposed begins to fall. The solution is to drop the reg output pressure although to what exactly is difficult without the ability to measure it or the pressure at which the gun is operating.
     
  3. ratty

    ratty Member

    Joined:
    Apr 19, 2013
    Messages:
    40
    Location:
    Rotherham
    Club:
    Anston
    Cheers for the reply .
    I was removing the reg so the fps would go up all the way through from full to empty (180-100 bar) at about 2fps per shot.

    I've now gone for plan B and serviced the reg and reduced the height of the standoff by 2mm so the seal that was leaking isn't over the small pit in the cylinder.

    As you say just need to check what happens when it drops off the reg to be safe.

    Put it all back together and short stroked the hammer a little 767fps first shot and it's not shifted yet .



    Time to stop fiddling now
     
    cloverleaf likes this.

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