Centrifugal Clutch fell apart

Discussion in 'Motorized Bicycle General Discussion' started by geoldr, Jan 28, 2012.

  1. geoldr

    geoldr New Member

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    Hey guys, so I was replacing my clutch pucks because it keeps slipping, but before all of that i had to take of my centrifugal clutch.

    All those times I was worried about it not being on there tight, well I guess it is. Using the tool that it came with, the clutch fell apart into 4 pieces. The part that goes onto the crankshaft is still on the crankshaft.

    So is it possible to put back together without a welder? Or do I need to buy a new one?
     

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  2. rohmell

    rohmell Active Member

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    Nothing bad or wrong happened.
    I usually file the egg-shaped hole in the weight assembly so that everything comes apart easily like it did for you. I do this in case the manual clutch portion needs servicing, so that the centrifugal clutch stuff can come off easily without having to pull off the tapered piece that locks onto the crankshaft.
    On some clutches that I have received, the fit is loose, and on some they are locked together in a death grip. You must of had a death grip version, so you may have thought that the parts were welded together.
    On some clutches, when the bolt is removed, you can tilt the bike to the right and the clutch assembly will fall off into your waiting hand.
    Just reassemble, and everything will be fine.
    The hardest part will be reassembling the sprag portion, with those tiny little cylinders. Use some thick grease to hold them in place when reinstalling the keeper.
    You might have a hard time getting the weight assembly back onto the part that is on the crankshaft, so just file the egg-shaped hole and matching boss on the other piece until everything fits back together.
    The bolt that threads into the crankshaft is what holds everything together, and the egg shape is what prevents the parts from rotating individually.
    Don't file too much, just enough so that the parts can go together and be removed easily.
     
    #2 rohmell, Jan 29, 2012
    Last edited: Jan 29, 2012
  3. geoldr

    geoldr New Member

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    Oh ok very cool. When it first came apart i just put everything back together and asked myself if it would be OK to just put the bolt back on and leave it like that. I guess it is. And you're right, for servicing this is really nice to have because you don't have to take it off the crankshaft.

    I am making clutch pads out of spare sprocket clamps I have, after putting it all back together I will post here if I need anymore help with putting the CC back together.
     
  4. wan37

    wan37 New Member

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    Geoldr In your picture I didn't see the spring keeper make sure you have it on there too.It kinda holds the cylinder ring in place.
     
    #4 wan37, Jan 29, 2012
    Last edited: Jan 29, 2012
  5. rohmell

    rohmell Active Member

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    Do you mean sprag keeper, maybe? If so, it can be seen in the first pic, upper right corner.

    EDIT: Well maybe not in the corner, but at 1:00 from the clutch bell.
     
  6. Pucksterpete

    Pucksterpete New Member

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    I too have just removed the CC for a quick maintenance. Thanks to Rohmell's advice all went well. But one thing is happening now. 1st let me tell you I am running a sbp jackshaft and pull start. So, I can either start it from pedaling and releasing the old clutch lever or use the pull start. With the weather very cold right now, its easier for me to pedal start the bike. So here is whats going on now.

    After re-installing the CC, I went to pedal start it and try to turn over the engine and it wouldn't turn over, it felt like I was stripping something when trying to pedal (lots of force). So, tried a few times with the pull start, the engine would turn over but not start, no big deal, use to that because of the cold. Tried again with pedaling, this time it turned the motor over and started, there wasn't any slipping from the CC, she rode fine. After having the engine running for a while, shutting it down and re-starting it again by pedaling no problem. It seems after a good warm up she starts fine either way.

    Never had it lockup like that before after the 1st install of the CC. So, I'm not sure what is causing it. I'm pretty sure all the pieces of the CC are put back together right. Anybody with the some ideas would greatly appreciated.

    Tnx

    Pete
     
  7. rohmell

    rohmell Active Member

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    Maybe your small clutch cover was rubbing. There are four ways that it can go on, and perhaps it was installed in a direction different than before, and it has to grind a (new) slight clearance into the cover.
    There is no guarantee that the small cover is perfectly flat and symmetrical!
     
  8. Pucksterpete

    Pucksterpete New Member

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    Nope, that can't be it, for I didn't have the cover on after putting the CC back on. Could it possible be the mounting bolt is on too tight, putting too much pressure on the weight/friction assy to the sprag keeper? I will see how she is in the morning from a cold start.

    Tnx

    Pete
     
  9. Pucksterpete

    Pucksterpete New Member

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    Rohmell correct again. The spring holding the sprag keeper needed more tension on it. That was causing the CC to slip and not grab when pedaling to turn over the engine. I actually had to make a spring for the one I had was all bent out of shape. I used a spring from a adjustable bar stem, its a little heavy duty spring and that did the trick. No more slipping. Thanks to Rohmell, your the man.

    Pete
     

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  10. rohmell

    rohmell Active Member

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    That's great news.
    Glad to hear that your CC is working correctly again!
     

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