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Wierd clutch problem yz125

Discussion in 'Big Bikes' started by brentn, Aug 7, 2009.

  1. brentn

    brentn Rookie
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    My brother's YZ 125 (03) has a strange clutch problem..
    When the bike is off, you can put it in first and pull the clutch all the way in and the clutch is still engaged and the bike will not move.

    If the bike is in idle, and you pull the clutch in all the way and pop it into first, it stalls but does not lurch forward at all.

    If the bike is running and you put it in first with the clutch all the way in and give it high revs it will not stall, and when he of course lets the clutch out slowly he gets going no problem.

    I checked his clutch cable and it seems to be ok, the tensioner on the lever is in fact all the way out so that the cable is nice and tight. I also checked the engine where the clutch cable hooks up to the clutch arm (is that the right name for it?) and it is defenitly moving quite a bit when you pull the clutch all the way in and out...



    At first I thought that maybe his cable has stretched, but it's tight and looks like it's engaging fine, but it's not.

    What could be wrong internally? Cause I'm thinking that this is probably the issue is something with the pressure plate maybe... I have no idea now.

    Have any of you guys seen this kind of issue?

    I really appreciate the help.
     
  2. Matt90GT

    Matt90GT Rookie
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    your clutch plates are stuck together.

    When is the last time you changed oil in the tranny?

    First thing to do is dump the oil, open up the clutch cover, remove the pressure plate and all the clutch plates. Pry them apart, clean them and then reinstall back into the basket. Fill with oil and you should be fine.
     
  3. brentn

    brentn Rookie
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    awesome, thanks buddy. The bike has been abused, and my brother doesn't know jack **** or cares to know jack **** about maintaining it. He hasn't changed the tranny oil all summer, since he got the bike, when me and my other brother do our oil changes every time we go out for the weekend.

    Is there a specific torque setting for the pressure plate bolts on this model of bike? Or should I just tighten them up and use some blue loctite in a criss-cross pattern?

    Thanks for the help
     
  4. BSWIFT

    BSWIFT Sponsoring Member<BR>Club Moderator
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    This is not a strange problem. Fairly common.
    1st, you should have a small amount of play in the cable, about a dime thickness.
    2nd, turn the gas off and lay the bike down on the left(gear shifter)side.
    3rd remove the clutch cover and inspect the basket. The oil will remain in the bike.
    2 posibilities.
    First is "notched" clutch basket fingers. This can be repaired if it is not too severe. Remove the preasure plate, fiber, and metal plates if these are very rough, you'll need to go ahead and drain the oil and lightly file the clutch fingers. The plates need to freely expand when the clutch is engaged, the notches fight or prevent the expansion of the clutch pack. Check all of the plate splines and tangs for sharp edges and file lightly. Clean everything thoroughly and reinstall. Fill with oil and ride. If the notches are extreme, the real cure is a new basket, preasure plate, and clutch plates.
    Secondly change the oil using a vicosity suitable to ambient temperature in which you ride. I personally use ATF Type F and change it often. @ a 1.59 a quart I can change it frequently. I've experienced better shifting and less clutch noise using ATF Type F. I you don't like this idea, use what is recommended by Yamaha, Yamalube. Great oil but a bit pricey in comparison. Whatever oil you use, change it ever 2-3 rides. You'll see improvement and your clutch will survive a bit longer.
    Matt's advice is probably the FIRST thing to do.
     
  5. Johnisenberg

    Johnisenberg Rookie
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    I have a 1999 yz 125 an I was wondering does oil have to be in the case for clutch to have pressure because I tore mine apart an put new clutch cable an have no clutch pressure I just wanted to make sure nothing was wrong before I put oil in it.
     
  6. High Lord Gomer

    High Lord Gomer Poked with Sticks
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    That has nothing to do with oil. If by "no clutch pressure" you mean that when you move the clutch lever you don't get any resistance and the clutch doesn't disengage....

    A new clutch cable will require adjustment to get it to function properly. In addition to the adjustment at the clutch perch there is also an adjustment in the middle of the clutch cable. It is a metal section where one side can screw into/out of the other and has an extra nut to lock it into position. It sounds like the outer covering of the cable is not long enough so loosen the lock nut and screw the two halves apart until you get tension. Once you get it set to the correct length, tighten the lock nut again.

    Ideally you want to the adjustment at the clutch perch in the middle of it's range and have 1 or 2 millimeters of slack that gets taken up before moving the clutch lever begins to disengage the clutch.

    Let us know how it works!
     
    Okiewan likes this.
  7. Johnisenberg

    Johnisenberg Rookie
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    I got pressure now but when i pull in clutch it not releasing at all if I shift it in higher gear it get easier to move but for some reason the clutch is not engaging is the clutches bad?
     
  8. High Lord Gomer

    High Lord Gomer Poked with Sticks
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    First...what all did you take apart and what items did you replace?

    If you replaced the fiber clutch plates and didn't soak them in oil beforehand, they could very well not allow any/much movement.
     
  9. Johnisenberg

    Johnisenberg Rookie
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    No it's a Hinson clutch I just bought the bike it's a 1999 yz 125 it had oil in it I got put top end in it an I was trying to figure out what wrong with clutch I got pressure but when I pull in clutch it not releasing an if I shift it up in like 6 it moves a little easier but still don't release all the way I was wondering what could cause it so I could replace it
     
  10. High Lord Gomer

    High Lord Gomer Poked with Sticks
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    Ahh...so you didn't take the clutch apart at all, just drained the fluid when you changed the top end?

    In that case, put transmission fluid back in it and start it up. It may be that it just needs to have in it to get back between the plates and it won't drag so much once warmed up.

    It is also quite possible that the basket is notched and the grooves are keeping the plates from separating when you pull the clutch lever. I put together a step-by-step set of instructions a few years ago for replacing clutch plates in an FZ1.

    http://themxtrack.com/Fizzy/FizzyClutch.html

    In it are some pictures of an ok clutch basket:

    http://themxtrack.com/Fizzy/DSC01865.JPG

    as well as a damaged one

    http://themxtrack.com/Fizzy/DSC01597.JPG
     

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