happy time motor

Discussion in 'Frame Mounted Engines' started by fatboy67, Apr 6, 2008.

  1. fatboy67

    fatboy67 Member

    Hi to all,
    Well Sorted the carbie problems on my 48cc 2 stroke Zbox motor, and it was running great. BUT I was riding it today for a short Sunday ride to help build up the miles for running it in. Before I go to all the trouble of pulling down the whole thing others may have some ideas. Well I was riding along and all of a sudden the motor revved hard like I had all of a sudden pulled on the clutch ( like a car slipping out of gear into neutral ) I revved the motor and the bike was going nowhere. I pulled over and stopped. I checked the chain this was OK. I pushed the bike with the clutch out and there was no resistance. It seemed at first like the clutch had **** it self. But low and behold it started working again. I peddled off and dropped the clutch and the bike started I rode about 10 metres and it again popped out of gear,, then popped back in gear I rode about another 30meters and all of a sudden the rear wheel locked up. I pulled the clutch in ( IT WORKED ) and peddled the bike home. Once I was home I tried manually pushing the bike but it seemed locked. I pushed the bike backwards this seemed to unlock it I then was able to start the bike it runs but has some internal noise. So I don't want to ride it until I work out what happened. I mean like I would be silly not to fix it now, as there is a definite noise and no doubt that noise is some thing that's hanging by a thread.
    Hey this motor has only done about 30 kilometres about 18 miles. I don't know how I would get on talking to Warren about this. I don't think they have any such warranties
    I'll tell him anyway
    Thanks Gilbert.......
    Last edited by a moderator: Dec 15, 2015

  2. azbill

    azbill Active Member

    sounds like maybe you sheared the woodruff key for the engine sprocket
    search 'woodruff key'
    it might also be the key for the clutch plate
    hope this helps
  3. fatboy67

    fatboy67 Member

    ye woodruff key

    Hi bill thanks for your reply.
    I took off the cover for the clutch and found a piece of metal which a I think is a piece of a woodruff key. I think the reason the back wheel locked was when this piiece came out it jamed up between the fly wheel and the outer case body. But the straing thing is that once I freed up the fly wheel the engine runs as normal the sproket doesn't slip/free wheel,,,may be there is still a little piece of woodruff key stuck in the key way. I have put some pics in sorry about the quality. If possible have a look and see if you think this looks thike a piece of a woodruff key.
    How many keys are there??? is it 2,, one on the chain sproket and one on the clutch sproket???? I don't think the pics worked
    Thanks Gilbert..............