Clutch Clutch not engaging anymore

Discussion in 'Transmission / Drivetrain' started by Sylas, Mar 6, 2015.

  1. Sylas

    Sylas New Member

    I have a standard 66cc happy time motor that has been running fine for roughly a year. Yesterday I pedaled to start the bike, and it started normally. Then when I went to give it gas, it just revved the motor with no power going to the wheels..just as if the clutch lever was pulled in, or the chain got thrown off. Since I don't have a kill switch, I had to pull the spark plug boot to kill the motor. I did the standard troubleshooting with the pads, and with the bar and ball bearing and cable, and all seems functional. I took it back out and pedaled down the street, and it acts the same whether lever is pulled or not..the only difference is that I hear clutch chatter when lever is pulled. Seems that something internal has given way, but I couldn't really find any cross section schematics of this motor, and I don't know where to start looking. I know that the clutch is not just slipping. Can anybody offer a suggestion as to what I should look for? Does the motor actually drive the small sprocket that is mated to the larger sprocket on the clutch side? Any help will be greatly appreciated. Thanks
    Last edited: Mar 6, 2015

  2. Sylas

    Sylas New Member

    Ok, after some further investigation, I realized that there are slots on the small gear next to the larger clutch gear, and on the shaft that it sits on. Ironically I had a broken key, so I filed it down to fit in the slot, and then carefully tapped the gear on with a hammer, while holding the "key" in place with a flat head screwdriver. I now have my clutch again...for how long I do not know, but if this happens again, or the new key gets sheared, I'll know where to start looking. Does anybody have a recommendation on materials to use next time something like this happens? Or even a way to go without the key at all?
  3. Sylas

    Sylas New Member

    And then after MORE investigation, I realize that I need a new WOODRUFF KEY. The makeshift key I fabricated lasted roughly 2 miles and then must have sheared away..probably causing all kinds of other problems. But for right now, it appears that I need another WOODRUFF Key. How do I handle an expanded keyway?...I don't even know how to take out the shaft of the system that I'm talking about. Somebody please!! Point me in the right direction, and I will gladly post back what will ultimately end up working for me. I refuse to let this motor dominate me!