YPVS adjustment problems...

  • Hi folks, hope you can help.

    My pink 1994 Dt125r seems to have a problem not opening the powervalve completely.
    When I turn ignition on, the PV does the cycle, and I've adjusted it so the holes line up.But when I rev the bike in neutral, the PV doesnt fully open, and when I ride i cant seem to rev past 8000rpm, and its got very little topend compared to what it should.

    If I jam the PV open, it looses bottomend like it "should" and have great topend.
    Currently, or as a test one could say, I have the PV adjusted like this. Why isnt thefully op This enables the PC valve to be somewhat closed when riding normal, and opening fully as the bike revs out: http://www.tenere.dk/forumnew/uploads/987/Ypvs.JPG

  • @Jens-Eskildsen number 1 need to go out more and 2 in more

    you should turn the pv to line up with the full power mark in the cylinder ( the little hole )
    and then adjust cables to make tight then turn key on and off and after its sound thingy it should stop and line up with the full power hole .........

  • The YPVS won't move as it should in Neutral.

    That doesn't look setup up correctly to me.

    Don't line it uo with the hole, rather take the exhaust off and make sure your adjustments make the powervalve flush with the exhaust port. Then you know for sure.

  • Aiden: I know its not setup like it should, problem is that ypvs doesnt seem to open fully when I adjust it so the holes line up. The above picture was taking after putting my finger in the hole.

    The PO recently gave it a new topend, perhaps some other things need adjusting. Can the black plasticthing which hold the ends of the cable be mounted wrng in some way? Doesnt look like it to me, but have to ask, as I really cant figure this out.

    Calum: Why wont the ypvs move properly in neutral? It only seems to "advance" up so the holes line up, but the ypvs need to moe way further for it to be flush with the exhaust. Thanks for the help so far, really appricate it, keep it coming 🙂

  • Your powervalve is spinning the wrong way but the looks of it.

    You need to swap over the two cables.

    Watch my video. That's all you need to do to sort out the powervalve.

    Engine off. Just switch the ignition on and off so that the YPVS motor turns it like it does on my bike.


  • Mine is setup that way aswell. But if i lign up the holes, the servo wont upen up fast that hole when I rev the bike (which isnt fully opening the PV) so i had to set it up way past the hole.

  • IF yours is setup exactly how mine is in that video and still no joy then it means either busted powervalve controller. Busted CDI ot restricted Cdi I

  • No restricted cdi for sure. Is there any way to troubleshoot the powervalve controller?
    Could the PV be out by 180 degrees? Because its not anything near fully open when the holes ligne up, which I think it should be? It doesnt seem to be 180 degrees wrong tho, more like 20

  • @Jens-Eskildsen Have you made sure the valve is flush with the exhaust port when it's in fully open position?

  • I've marked just about the spot where the valve is fully open, and flush with exhaustport.
    This is also where the servo moves to when i rev the bike.
    So if i lign the holes, it will only move up to about where it sits now, thus not opening the valve very much.
    It seems like the whle assembly is somehow 1/16 of a turn out.

  • Gt it adjusted not, dont now what went wrong, i think the black part wasnt properly seated on the valve.

    Next problem is to sort out a rich condition. Bike starts ni problem without choke, and wont rev out. Makes more power if I close the throttle a bit. Midrange is crisp after lowering the needle.

    Bike has sat for a while, but it seems all pasages in carb is clear, and the choke is working as it should.

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