Clutch won't disengage on motorized bicycle

Discussion in 'Frame Mounted Engines' started by Phantom Shocker, May 2, 2011.

  1. Phantom Shocker

    Phantom Shocker New Member

    Hello. Can anyone help me out here? Okay this is my problem...
    I ran this motor I'm using on another bike last summer and it ran perfect when I parked it. I put 40 miles total

    on it since new. Over the winter I decided to mount it on an OCC Schwinn Stingray. Now my motor sprocket is

    lined up with the rear sprocket so there is no issue there. But for some unknown reason my motor is

    engaged (in gear) and will not dis-engage. Now the clutch arm moves, and the push pin is not dented or bent

    and spinning the "flower nut" is not an issue either. It spins freely. My cable is not stretched, everything

    seems very functional but the clutch will not dis-engage and free-wheel for some reason.... It just stays in

    gear. My only last thought is does the drive chain need to be at a certain angle or position? I have plenty of

    pictures if anyone needs to see the chain position or anything else. Thanks in advance!!!

  2. DuctTapedGoat

    DuctTapedGoat Active Member

    So, your clutch plate will not lift off of the pads - sounds like you still need to work on the flower nut! Check the spring below the plate and make sure it's not jammed and that it is pushing the plate off the pads.

    Honestly, I don't believe you when you say "it spins freely". If your clutch plate spun freely it would be disengaged.

    4 step clutch adjustment:

    1. Put the clutch lever in the locked position.

    2. Adjust the clutch cable to get the clutch's camshaft to be perfectly flat against the pin.

    3. Adjust the flower nut until your bike rolls freely.

    4. Fire up the bike and lift the back wheel off the ground and lock the clutch. Your back wheel will not move if it is adjusted properly.
    Last edited: May 3, 2011
  3. Phantom Shocker

    Phantom Shocker New Member

    Clutch won't disengage...

    Thank you for your reply!!!
    The "flower nut" turns by hand, not the clutch plates themselves, they remain engaged. But it only spins to loosen it because the "stopper screw is in the way. It's stuck on and if I have to remove it, it will strip and I'll have to tap it out. Do you think the spring is too compressed from sitting all winter engaged? It was stored indoors, so weather isn't a factor. When I go to disengage the clutch, I can see the flower nut move out away for the plate and it's under good pressure still but it doesn't stick out far enough to pass the screw.
  4. DuctTapedGoat

    DuctTapedGoat Active Member

    Adjust the flower nut to get the stopper screw between the notches. Use pliers or vice grips to loosen the screw if it's still really stuck, this will remove it while keeping it from stripping.
  5. Phantom Shocker

    Phantom Shocker New Member

    Well I got the set screw off, tried adjusting the flower screw either way and the motor is still locked in gear. So I removed the outer clutch plate and it was stuck in place as well. I was able to separate the two clutch plates and it's still in gear. When I spin the rear wheel, the motor turns like it's still in gear. Man I'm sorry to be such a pest but i'm banging my head off of the wall here. Thank you very much for the help! I'm thinking it might need a new clutch set up. It's the only logical explanation I can come up with next unless you know a trick.
    Thanks again!!!
  6. DuctTapedGoat

    DuctTapedGoat Active Member

    Not being a pest by any means - sounds like you've got a genuine problem!

    I haven't overhauled the bottom end on these things, but I'll see what I can come up with.
  7. Phantom Shocker

    Phantom Shocker New Member

    Nevermind... I got it! It was rusted and froze. It's fixed! Thanks again for your advise!!!
  8. DuctTapedGoat

    DuctTapedGoat Active Member

    It sounds like it would be your clutch return spring, which is located inside the bottom end, which means you'd have to split the case. A common thing, but something that I haven't dealt with, is a sheared woodruff key. I've heard fairly commonly that they can shear and get jammed up in a gear, either causing stuff to get stuck in one position or even seizing the entire thing.

    This link is great - it's a 3d modeled exploded view of the full clutch.

    When you got your motor, it would have came with sprocket removal tool, which you use to remove the flywheel inside the crankcase. That's where you'd be able to check the woodruff key, which would be easier than splitting the case, so I'd start there.

    Though - please, anyone who's rebuilt a clutch, chime in! I don't want to give nonadvice due to lack of experience in a full teardown.
  9. DuctTapedGoat

    DuctTapedGoat Active Member

    Oh - nice! What part was rusted out?
  10. linglanglong

    linglanglong New Member

    flower nut stuck

    Hey my clutch wont disengage and my flower nut is stuck. i have tried hitting around it with a rubber mallet but it seems the pucks are still stuck.
    does anyone have any ideas?
  11. HeadSmess

    HeadSmess Well-Known Member

    ride it :)

    itll loosen up after ten seconds, which was the case with the OP as well. they get stuck together when left for too long.

    youll only get the flower nut to turn when you pull the clutch lever, taking the spring tension off of it ;)
  12. wargood23

    wargood23 New Member

    Got a problem

    So when i took the motor off my bike to try and fix my clutch since it wouldnt disengage i found out i needed to adjust the clutch plates and such. So i did that but now the little pin that is compressed to release the clutch is sticking out really far. I have no clue why its sticking out and id like to know if its an issue with me working on the clutch plates. Any ideas?
  13. HeadSmess

    HeadSmess Well-Known Member

    which pin?

    the 8mm (5/16) one on the left hand side, under the small cover with 3 screws? should stick out about 8mm or so... pop it out, there should be a ball behind it...make sure it doesnt get lost! then whack some grease down the hole, reinsert... so yes, when the clutch is together, it SHOULD stick out.

    or the threaded stud on the actual clutch side, which takes that funny nut? it will stick out a fair bit if either of two things are happening... 1. the clutch pads are worn out, and youve reached the end of adjustment. 2. you adjusted the clutch, but forgot about the cable or the lever that actuates the clutch, and its pushing it, as if youre squeezing the lever...but arent!

    erm...hate doing it but this calls for it!

  14. wargood23

    wargood23 New Member

    the one one the left its sticking out TOO far and wont allow me to put the plate back on so any ideas?
  15. HeadSmess

    HeadSmess Well-Known Member

    thats sort of normal...spring tension, you see... as long as the gap between cover and case is about 5mm, alls good.

    just tighten screws gradually, going round em a few times, rather than doing one at a time, until tight. (gap will close up)

    or loosen off the flower nut on the other side which is pretty hard to do unless you already have the left hand cover on, to let some pressure off of it... ie, you need to be able to disengage the clutch to remove the nut(easily).
  16. wargood23

    wargood23 New Member

    Thanks i got it fixed now all i have to adjust the clutch and buy the screw that keeps the flower nut from unscrewing. Know where i can get one? Also how can i clean the magnet. Its "alittle" rusty
    Last edited: Sep 15, 2014