Motorized bike clutch slipping

Discussion in 'General Questions' started by Kash66, Aug 16, 2015.

  1. Kash66

    Kash66 Member

    Ok so I have a 2 week old engine on a mountain bike and the bike runs great on flat surfaces but once the surface becomes a little up hill, the bike revs but doesn't move fast, I can hear a grinding, squealing noise from the engine. I don't know if the clutch pads are the problem because the engine is only 2 WEEKS OLD. Should I open it up and degrease the pads.


  2. Matt-83

    Matt-83 New Member

    I had a similar issue with my bike, 80cc 2 stroke. When I released the clutch it was not grabbing enough to start the motor. After investigating I found that I had the clutch linkage too tight. There has to be no drag on that lever at all when the clutch is out, to the point where the clutch lever wiggles around. After that my clutch engages completely with no slippage. Unfortunately now the clutch lever wont hold the clutch completely in while in the locked position, it grabs just a little, not enough to stall the motor but to the point where I do not let it idle at a stop without holding the clutch lever in all the way.

    Just make sure your clutch is completely out- no tension on cable when lever is released. If it is still slipping then there could possible be something else wrong.
  3. Kash66

    Kash66 Member

    Ok thanks so you know what else could cause my bike to slip.

  4. Matt-83

    Matt-83 New Member

    Other than the clutch linkage not allowing tie clutch to fully engage I honestly could only guess. Could be a bad clutch from the factory, or something got on it causing the slip. I've never seen one apart so not sure about how all the components work.

    Good luck
  5. Kash66

    Kash66 Member

    ok thanks dude
  6. crassius

    crassius Well-Known Member

    clutches rarely fail

    when adjusting clutch, one adjusts cable first to have very little slack, then with lever locked adjusts flower nut until clutch is just barely free spinning, then release lever and re-adjust cable and re-check flower nut at lock position (repeat until both are right)

    the amount of 'grab' a clutch will then have depends on the distance the lever moves between the unlocked & locked position - sometimes a defective lever will not have much difference between these 2 positions and should be replaced or have the housing stop filed down until the lever sits farther forward when released

    there is also an internal spring adjustment, but rarely needed