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MC21 RC Servo operation. How to tell if it's working properly?

Discussion in 'Honda 250cc 2 Strokes' started by KICKERMAN360, Feb 6, 2015.

  1. KICKERMAN360

    KICKERMAN360 Well-Known Member

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    So basically I've swapped all the SP engine in and it fires up perfectly ( somewhat surprising, expected to forget something).

    Anyway, I was setting the RC Servo and power valves and followed the guide on NSR World. They said turn the ignition on and let it go to the start position. And then unplug the TPS and it should turn again to another position and adjust the valves from that point (Don't worry, that's just a small summary. Did it *exactly* how it said). Anyway, it only moved to the first position. So I set the valves to that (using the quick method, drill bit to align the valves) and it seems to be alright.

    Fired it up and I'm not exactly sure what movements the valve is supposed to do. Does it open up a 2k RPM and stay open?

    I shot a video of it, revving to roughly 7k RPM and back. It seems a little sluggish too but I guess the RPMs would move at a slow enough rate whilst moving to keep up. I really need to mockup a small fuel tank for testing purposes.

    Here's a video:



    In hindsight, when I got the MC21 with the R motor I should have observed how it worked.
     
    KICKERMAN360, Feb 6, 2015
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  2. Neal

    Neal Active Member

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    That's exactly what it does , when the bike is not running and you turn the ignition on the powervalve motor will set itself . If it is in the correct position when it was last turned off it will not move the next time you turn it on . If you manually move the motor off its preferred position and turn the ign on you will see that it resets itself .
    When the bike is running they will move again once the revs are high enough .
     
    Neal, Feb 8, 2015
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  3. KICKERMAN360

    KICKERMAN360 Well-Known Member

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    Hmm, but I was mostly asking what it does through the rev range.
     
    KICKERMAN360, Feb 9, 2015
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  4. Fox McScrooge

    Fox McScrooge Well-Known Member Premium Member Contributing Member

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    I think it depends on whether you have done the wire splice with the MC21 or HRC ignition with the 28. I've got the HRC 030 ignition in mine. It comes on the pipe from about 8K. I've never actually looked to see when the valve fully opens but I would imagine it's somewhere above 5-7K. If you search the NSR forums I guarantee the question will have been asked and answered. Sounds like the PGM is working mate which is a good thing.
     
    Fox McScrooge, Feb 9, 2015
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  5. KICKERMAN360

    KICKERMAN360 Well-Known Member

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    Yeah, it looks like it's working fine. I saw a post a while back which describes how it opens but it seems a little twitchy and slow. Like, the RPMs jump up (I know on my CR125 when the power valve doesnt work it's slow as) so everything seems good. Anyway, I ordered new airbox inlets, filter and tank rubbers so once I have everything ready to go I'll take it out and see how it feels.
     
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    KICKERMAN360, Feb 12, 2015
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