Clutch Help with clutch/kick starting!

Discussion in 'Transmission / Drivetrain' started by GorillaPerry, Feb 11, 2012.

  1. GorillaPerry

    GorillaPerry New Member

    Hello! first time posting (second, including the 'introduce yourself' thread).

    here is my problem. I just put together an "80cc" 2 stroke, and it won't turn over! So frustrating.

    I scoured the forums and tried everything I thought it might be: checked for spark, checked carb bowl, disconnected the kill switch wires. everything I checked seems to be okay. Which leads me to think it might the clutch, I checked the clutch cable, no slack, I can feel resistance when I disengage the clutch. My knowledge in small engine repair is limited, and am at my wits end here :annoyed:

    does anyone know how I might go about seeing if the clutch needs to be adjusted, and if it does, how would I go about doing that? or if a similar question has been answered where I might find the answer? I looked through the forums and couldn't find a previously answered question.

    Should I try taking it to a moped mechanic?

    thanks in advance! :grin5:

    EDIT/ADDITION: I'm almost positive it's the clutch, I had heard the the piston "thumping" (compressing) up and down when I would roll the bike forward about a week ago, now I've got the clutch installed on there, I don't hear the piston compressing at all.
    Last edited: Feb 11, 2012

  2. motorpsycho

    motorpsycho Active Member

    first things first.
    If you say that the engine won't turn over, in general that means that the engine is locked up (piston won't go up & down) or the clutch is slipping badly.
    so, is the piston going up & down?
    if the clutch is slipping bad, the piston won't go up & down and the engine won't run.
    when you try to roll the bike forward does the rear wheel keep rolling or does it lock up when you let the clutch out?

    roll the bike forward(but don't put any weight on the seat) with the clutch lever released. if the rear wheel does not lock up, then your clutch is slipping badly. 9times out of 10, the problem you are describing is a mis adjusted and slipping clutch.
    roll the bike forward with no weight on the seat and let the clutch out, does the rear wheel lock up?
    if the rear wheel locks up then your clutch is adjusted right (or in the ballpark anyway)

    sometimes you will have to play around with the clutch arm (on the left side of the engine where the clutch cable goes) to get it just right.
    with the clutch handle released, you should be able to wiggle the clutch arm back & forth with your fingers...there should be no tension against it and it should feel "loose" when you move it with your fingers.
    with the clutch handle squeezed in, the clutch arm should be tight, and you should not be able to move it back & forth with your fingers. it should feel "tight" when you try to move it with your fingers. (you may be able to move it a little if you try hard enough).

    if you have the clutch arm set in this fashion and it appears that the clutch is still slipping (the rear wheel does not lock up when rolling the bike forward, without any weight on the seat) you may have to go in and adjust the clutch at the flower nut.
    the clutch itself is located under the right side engine cover. remove the right side engine cover and you will sea the clutch (towards the rear of the engine). in the center of the pressure plate, you will see a big flower looking nut with a locking set screw. theset screw is there to keep the flower nut from backing off while the engine is running.
    remove the set screw and then turn the flower nut in to get more clutch, out to get less clutch. (if it's slipping you'll want to turn the flower nut in (clockwise).
    this takes time and patience and if you are unaware of how a clutch is supposed to operate, you may not want to go here.
    if you do go here, and try this make sure that you re-install that set screw because without it, the flower nut will back itself off, and the clutch won't work at all.
    there are other people who may be able to describe this process in more detail if you need it. I just know how to do it, and sometimes it's hard for me to explain things like this to people who don't have much mechanical ability. it's simple for me to do because I know how to do it and it's hard for me to explain something that's easy for me, but difficult for others to understand.
    Last edited: Feb 11, 2012
  3. wan37

    wan37 Member

    Last edited: Feb 11, 2012
  4. Big Red

    Big Red Active Member


    I think it's a good video wan, I'm not sure, the sound just went out on my computer. STILL, I didn't "see" the guy explaining that it's easier to adjust the flower nut if you pull in the clutch lever or arm. This will loosen the clutch and make turning it easier. Otherwise you just wind up trying to beat the thing into place and end up with a mangled flower nut.
    Big Red.
    And also, Check for ANY oil on the clutch pads. It don't happen often, but a bad clutch side crank seal will throw oil on the pads. I got a brand new one like that once. An hour or two of riding and the clutch will start slipping.
    Last edited: Feb 11, 2012
  5. wan37

    wan37 Member

    Here I found some other's too but way to detailed.So hope this helps.
    Last edited: Feb 11, 2012
  6. wan37

    wan37 Member

    Last edited: Feb 11, 2012
  7. GorillaPerry

    GorillaPerry New Member

    wow thanks for all the help! I'll try all that and get back to you guys, I am not positive that the piston isn't going up and down, I just wasn't hearing it at all (like I used to). But I'll check that first thing tomorrow. I know that when I engage the clutch the rear wheel does not lock up and rolls freely, not as freely as the clutch handled pulled but pretty freely none the less, so I will check that out as part of the first step to my trouble shooting. hopefully it's as simple as adjusting the clutch arm :s

    Thank you for the videos as well, haven't had a chance to watch them just yet but I will tonight and get back to you guys.

    thanks again!
  8. motorpsycho

    motorpsycho Active Member

    By this description, it sounds like your clutch is definitly out of adjustment.
    any time you release the clutch while just rolling the bike forward, the real wheel should lock up. if the rear wheel continues to turn with a slight drag on it, then your clutch is out of adjustment.