Bike will not move at all, Clutch locked

Discussion in 'Frame Mounted Engines' started by mastafoo, May 9, 2009.

  1. mastafoo

    mastafoo New Member

    When I completely assembled my 80cc motorized bicycle kit, everything looked good, and hooked up nicely. Aside from some chain length issues, I managed to set up everything so I could push the bike freely with the clutch in the Neutral position. When I began attempting to ride the bike and gain enough speed to start the motor, the clutch would lock randomly while still in the Neutral position. I think it locked when I had switched to the engine drive position, too. I could fix this by stopping, backing up a bit, and moving forward. Now, it did the same thing but is stuck for good. I can't move the bike in neutral, even after adjusting the tension cables. I'm stumped now... any advice from a hardened veteran?

    P.S. By lock I mean switch to engine drive, but as far as I am concerned it could be locked :(
    The chain also has a bit slack but never appears jammed...

    "red bat" 80cc China kit
    16:1 fuel
    Roadmaster mountain bike
    Last edited: May 9, 2009

  2. bluegoatwoods

    bluegoatwoods Well-Known Member

    On the opposite side of the engine from the clutch lever you'll see a removable cover. Take this off and you're looking at the clutch plate and pads themselves. I'll bet you need some adjustment there.

    But I can't carry this any further because I've never adjusted there before. I keep it in mind because I know I'll need to sooner or later. Still, I'm sure you could find some hints by searching "clutch adjustment" or something like that.

    Good luck.

    I see you're riding a Roadmaster. I have a few of those lying around. I've been thinking about motorizing one, but that frame looks like a tight fit. But it also looks like you've managed it. That's good news. I might just go ahead and do it.
  3. mastafoo

    mastafoo New Member

    Thanks for the info, I'll take a look and play around with the clutch - hopefully fixing it will be as easy as adjusting it. I'll post updates when I can...
    And yes, the roadmaster was a challenge but aside from the chain everything is a pretty nice fit. Feels pretty stable too.
  4. mastafoo

    mastafoo New Member

    Ok here's the scoop. I removed the plate and adjusted the so called flower nut in many different ways, with no avail. I also tried removing it along with the plate it was screwed on to so the friction pads were exposed. Nothing - the rear tire still wouldn't turn freely. I put it in neutral, I even pushed the little clutch lever as far as possible, and it was still locked in place. If the friction pads are exposed, I'm starting to think something internal is broken or something like that. I've notified the ebay seller and may replace the engine... If I can fix it now though that would be great. Any other ideas?
  5. Patdon10

    Patdon10 New Member

    I'm having the same exact problem as you are with my 80cc kit. The only difference is mine has never spun freely, no matter what I do. I'm curious as to who you got your kit from...we may have gotten the same kit from the same person.
  6. mastafoo

    mastafoo New Member

    ebay seller luckyearlybird or something like that... I'm not complaining yet - If I can get a new engine block from her that works I'm a happy camper...but fixing the current one is much more convenient, if even possible. Return policy is something like 7 days though...
  7. retromike3

    retromike3 Member

    I had a similar failure going down a hill today. what happened was the chain got jammed inside the drive cog space in the drive unit. The problem was my rear cog was not balanced and I had to much slack in my chain. So, wen the chain whipped a bit it got stuck between the cog and the inside of the housing, locking up the rear wheel and making it skid for about 30 feet. Hopefully I got the chain on right now.

  8. spad4me

    spad4me Member

  9. BoltsMissing

    BoltsMissing Active Member

    I posted this thread with pics, it seems the sieze clutch thing is becoming common.
    If you have the special tool that should have come with your kit, remove the cogs and tap out the entire clutch assembly.
    The slide ring is probably jammed up.
  10. spad4me

    spad4me Member

    The clutch being that bad is beyond reason.
    Please post the brand of this TRASH being sold as a bicycle motor.

    red bat?? Who sells it.
  11. mastafoo

    mastafoo New Member

    Good news! The metal cover over the little sprocket on the engine was bolted on so tightly that I couldn't get it off. I figured it had to be something in there. Well, I cooled the stubborn bolt off with some ice and use a cordless power tool to unscrew it. Inside was bunched up chain... I fixed that up and now it is free as a bird. The chain obviously had too much slack. I am going to put some pipe or metal strips in the engine mount to move it forward a bit and tighten the chain. The supplied pulley is out of the question, since it failed horribly.

    bootom line:
    Slacky chain = :death:

    Hopefully once I fix the slack I can get rollin!
  12. dan48cc

    dan48cc New Member

    please dont grind or cut anything, i think i might have the answer for you. it is so simple you will most likely laugh but i happened to me and after calling the seller this is what i was told.
    with the clutch locked to the engine. stand beside the bike and put your weight on the seat, walk the bike backwards. this will clunk and carry on but perservere. keep walking the bike backwards till you hear a big ping or a heavier clunk and the problem will be solved. it seems that these little mass produced engines are not always properly checked when leaving the factory and some of the clutch mechanisms have dags on them that cause them to jam. i did this on one of my bikes and fixed it first go. had to walk it back about 5 metres beforeit happened. let me know how you go.
  13. mastafoo

    mastafoo New Member

    Ahh yes, the sweet smell of burned oil and gas. I fabricated some spacers out of steel and they work like a charm. Chain is tighter, motor started on the first try! Yes!
    One more little bug though... The whole engine moves to the side after driving a bit and of course causes the chain to come off. I'm using the "big frame adapter".
    I'll try removing some rubber spacers between the washers on this adapter and maybe it will stay in place. If anybody has any tips I'll be overjoyed.

    P.S. sorry for not posting in a week, I was on a cruise lol
  14. mastafoo

    mastafoo New Member

    Fixed the movement problem as well, everything works fine now. Have been driving around for a few days. Clutch is a bit loud...sounds squeaky sort of. It shouldn't be slipping, I tightened it. I might try putting some rubber on the cover or look into a few other things.

    So far so good though, thanks again for the help everyone. I can't express how happy I am to have a working bike!
  15. RMWdave

    RMWdave Member

    i did a search on this and drug it back to the top of the board. my chain tentioner also failed miserabley last night just before the engine hit the sweet spot upon starting, when it lurches and jerks it came to a halt. the clutch arm is in "midfix" and is hard to disengage so i couldnt get it pulled in. There is no doubt damage done somewhere. i will check the chain in the morning HOWEVER here is where i may run into a problem.....
    first thing i did yesterday morning was go and reinstall the horrid tentioner to make a 5 minute ride to work. got it all done and tried to pedal with the clutch arm moved and and the lever then held by hand (hard to squeeze, needs a push to slack up first before it holds disengage) ANYWAY its locked solid. great i think, the rough stop probley siezed it i figured since it was, well. rough. i took the clutch cover off suspecting this to be the failure first. no missing teeth on gears, looks good.... then i move to the magneto side and put a wrench on the flywheel nut. turned over the engine with that but.... im ending there because i HOPE its not out of phase.....

    it did move the piston, so its not a cold siezure..... please tell me i can fix this. it looked like the nut simply tightened on the crankshaft at first while moving the flywheel as well.
    is there a woodruff key on it to keep it in place i hope?
    will try a check over a few other things tomorrow like the chain perhaps bunched on the drive gear.
  16. mastafoo

    mastafoo New Member

    My chain was definitely bunching in the drive sproket, and I fixed it by fabricating steel spacers for the rear mount, moving the rear wheel back, and making my own frame mount to increase chain tension as well as cutting the chain. Also...another big thing: look at how the chain enters your big sprocket. If the wheel is properly aligned the teeth will be in the middle of the space in each link. Mine entered to the side, which cased the chain to want to fall off, which it ended up doing many times.

    Oh and I removed the tensioner...I don't trust it at high speeds, but I might use it when the chain stretches after a while.

    Are you sure the tension cable is tight enough? Can you move the clutch arm with your own hand? If you can't, then it might be internal damage, but I doubt it. This is my first build, so I don't know much about these engines.

    Good luck, I'm sure you can fix this...
  17. RMWdave

    RMWdave Member

    im actually stepping out to check it out right now.
  18. RMWdave

    RMWdave Member

    turns out the chain had jumped, i am going to try and make a case saver insert for that area out of nylon.