Clutch cable and clutch adjusting procedures.

Discussion in '2 Stroke Bicycle Engines & Kits' started by GearNut, Sep 4, 2010.

  1. GearNut

    GearNut Active Member

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    Here is a deciphering of how to properly adjust your clutch cable and clutch flower nut.
    Always adjust the cable before adjusting the flower nut.

    How to adjust cable:
    1. Loosen the lock screw in the brass cable end until the cable can slide through it. Do not remove the brass cable end from the cable.
    2. While keeping the brass cable end in the cable hole on the tip of the clutch release arm , grab a hold of the end of the cable with pliers and pull the cable through the brass cable end until the cable is tight.
    3. Swing the release arm (with the brass cable end still in the tip of it) inwards towards the carburetor until it stops swinging. Do not forget to keep pulling the cable through the brass cable end as you are doing this.
    4. While holding the cable relatively tight and keeping the brass cable end in hole at the tip of the release arm, and the release arm rotated fully towards the carburetor, tighten the lock screw in the brass end.
    The cable strand between the cable housing stop thing on the top of the engine case and the release arm should almost be in a straight line now.
    You should barely be able to wiggle it. It should not be as tight as a piano wire though.
    About 1/32" freeplay.


    Adjusting the clutch:
    1. Adjust clutch cable as described above so there is only a little bit of slack, about 1/32", in the inner wire when the hand lever is released all the way out.
    2. Remove gear case cover from right side of engine.
    3. Remove lock screw from clutch outer plate. It's the little screw that fits into the notches on the edge of the center nut (called a flower nut).
    4. Squeeze in clutch hand lever until it touches the hand grip. Hold it in with the lock button or some tape or a piece of wire, zip-ty, ect.
    5. While pushing in on the outer clutch plate with one hand, tighten the flower nut until snug, just using your fingertips. Do not use pliers, ect.
    6. Unscrew flower nut 1/2 (180 degrees) to 1 full turn (360 degrees) out, aligning a notch on the flower nut with the hole in the outer clutch plate that the lock screw goes into.
    7. Install lock screw but don't tighten it just yet.
    8. Remove tape or wire from hand lever and let it release all the way out.
    9. Tighten lock screw for flower nut.
    10. Adjust clutch cable if necessary to give just a little free play to the inner cable when the hand lever is all the way out. You should be able to wiggle the clutch release arm a little.
    11. Install gear case cover and test ride. Every clutch is a little different.
    You may have to fine tune the adjustment of the flower nut by a few notches.
    __________________
     
    #1 GearNut, Sep 4, 2010
    Last edited: Apr 10, 2014
  2. killercanuck

    killercanuck New Member

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    *bookmarked for reference to the next person to ask :D
     
  3. Nougat

    Nougat New Member

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    Only thing I'd say is that no cable slack at all is necessary. My clutch handle doesn't even wiggle when it's out. It's possible that it depends on the kit.

    Oh, might be worth mentioning cable stretch, too.
     
  4. GearNut

    GearNut Active Member

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    The little bit of slack in the cable is there so there will be very little pressure applied to the clutch mandrel, bearing ball, bucking bar, and clutch release cam shaft while you are riding down the road. While I agree that the engine and transmission will still function just fine if you remove all the slack, leaving a little slack just unloads the clutch spring pressure from all the parts involved and reduces friction and wear.

    By slack I am not saying that the clutch hand lever should be all floppy and the release arm in the sprocket cover swings and wobbles all around.

    Cable stretch is normal and routine cable adjustment is part of proper maintenance.

    I am not trying to share a proper maintenance guide for these engines, although these methods would work just fine for a small portion of that application.
    This is more intended for new builders who are struggling with the Chinenglish instructions while assembling their first build and are not familiar with how a cable operated clutch should be set up.
     
  5. KCvale

    KCvale Active Member

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    And I would like to add some further info (with pics) ;-}

    Basic Cable Design

    A cable has two parts.
    There is the actual inner cable with connectors on each end in this case to the clutch handle and the clutch arm, and an outer cover.

    The outer cover is not for decoration!
    It is an actual crucial part of a cables mechanical ability to transfer force from one place to another in a flexible form!

    When you 'tighten' a cable with in-line adjusters you are not tightening the inner cable from point A to point B, you are adjusting the difference between the inner and outer cable parts.

    For example the kit locking clutch lever has an adjusting screw and locking nut.

    [​IMG]

    The adjusting part is the cone shaped part the cable cover fits in, the locking nut is the bigger ring.
    Make sure this is screwed in as far it will go before adjust the brass lock connector on the clutch arm side.

    If your clutch won't disengage after some inner cable stretch and outer cable shrinkage you can tighten it up by twisting the cone out and snugging the locking ring up against it to compensate.

    There is also one that is mounted on the motor itself under the Carb but it much harder to get to.

    Once the cable is adjusted

    It is very common for the grease in the bearing between the clutch plate and outer gear to the motor to dry on the literally slow boat from China trip to the US and warehousing, and pulling the lever does not seem to engage the clutch to disengage the motor from the drive sprocket.

    This is usually not the case at all and the clutch pressure plate does indeed move away from the friction pads, the dried grease just has the shaft locked to the gear.

    Pop off the right cover.

    [​IMG]

    Pull your clutch lever, that big sliver plate should move out towards you.
    If it doesn't go back to cable adjusting until it does.

    Now pay close attention to the locking screw and flower nuts position, mark them if need be for reference, then pull the flower nut lock screw and unscrew the flower nut.

    To make this easy lock your clutch lever in the engaged position and you can twist it off with your fingers if you push the plate down with your hand while doing it.
    The same goes for putting it back on.

    Pull out the pressure spring and you find the business end of what makes a clutch work.

    [​IMG]

    Understanding the Clutch

    Using that pic and my terms as reference, the little gear is the actual motor crankshaft output.

    The large gear is a plate that holds all of those little friction pads, and it 'floats' on a bearing that divides at the 'Bearing Seam'. That is usually what dries out and locks the motor to the drive train and needs breaking free.

    The silver pressure plate you removed earlier rides on the those 3 'Clutch Plate Float Guides' so it can be pushed away from making contact with the pads, but still staying connected to the output shaft, thus disengaging the motor from the drive side, but making contact when you release the clutch so the plate makes contact with the pads to the big outer gear.

    To Free Up That Bearing...
    A long flat head screwdriver works dandy for me.

    All you need to do is use two the Floating Guide posts for leverage and without the motor gear moving.
    CRUCIAL IMPORTANT NOTE!!! Do NOT use that center Disengaer Shaft as a leverage point!

    Give the screwdriver a hard push down and it should break free.
    If the motor gear moves you need to stop that from happening, the point is to break the bearing free.
    The gears need to not move, just the inner part to the drive sprocket to break it free.

    NOTE: if your drive train is hooked up to the wheel lift it so it will turn, that inner shaft goes directly to it.

    The common practice to keep the motor locked is to put a wooden dowel of some other thing that wont scar the cylinder wall but block the piston moving down the cylinder head from the plug hole, but as I look at this it seems to me you could just wedge a piece of plastic or something in where the two gears meet so they couldn't turn.

    It's not like you are breaking a piece of metal, it is just freeing up dried grease in a bearing.

    Once you have it free

    Clean out all the gunk between the pads and put a liberal amount of new grease (not oil) on that Bearing Seam and the gears.

    Adjusting the Flower Nut

    Put the spring and plate back on and put the flower nut about where it was.
    Lock your clutch in and roll the bike around, does it roll free?
    If not, back the flower nut off 1/4 turn until it does.

    Once it rolls free, let the clutch lock out and try.
    Does it engage to the motor?
    If so put your set screw back in (lockTight it of you have have it) and button it up, you are done.

    Remember, if you start getting clutch loss, you have two places to adjust for it, the clutch lever is just the easiest.
     
    #5 KCvale, Sep 5, 2010
    Last edited: Sep 25, 2014
  6. ncfootballchamp

    ncfootballchamp New Member

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    When I pull in my clutch, the big silver disc does not move, however the flower knut moves out. After step 4 in GearNut's "Adjusting The Clutch" instructions, I cannot follow them for whatever reason.

    Is my engine installed correctly? I ordered it from BikeBerry.com (2010 chinese whateveritscaled engine)

    Should I call them and ask for a new engine? Or am i dong something wrong?
    Thanks for the help
     
  7. GearNut

    GearNut Active Member

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    The plate may just be stuck to the friction pads, not really a big deal to overcome. I suggest unscrewing the flower nut almost all the way off then tapping the outer pressure plate (big silver disc) with a screwdriver handle. It should pop out like it is supposed to.
    If that does not work, remove the flower nut and gently pry the plate off of the clutch. A few of the friction pads may fall out but you can just stick them back into their pockets.
    Do not forget about the helper spring though, don't let it come out and surprise you.
     
  8. ncfootballchamp

    ncfootballchamp New Member

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    Ok thanks. Ill try that
     
  9. ncfootballchamp

    ncfootballchamp New Member

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    alright i took the plate off as well as the flower nut; i think the plate was stuck because I pried it and then felt the spring's pressure. Despite this, the clutch STILL is not disengaging the gear. To be clear, with the clutch engaged, I still cannot pedal the bike without the engine moving as well. What Is wrong with my engine?

    Thank you for the help. It is very much appreciated
     
  10. GearNut

    GearNut Active Member

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    It sounds as if the cheap a$$ factory grease in the bearings between the ring gear and hub has hardened up on you. Do as KCvale shows with the screwdriver trick to loosen it up.
    Pay close attention as to where the screwdriver is positioned. You absolutely do not want to put any pressure on the center release shaft bolt.
     
  11. KCvale

    KCvale Active Member

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    Absolutely crucial to not try to use the center shaft as a lever point.
    Thanks for making a special point about that gearnut, no such thing as stressing that enough.

    All you need is 2 of the 3 drive pins to wedge against to break that bearings dried grease free.

    If you followed all the directions, and the clutch plate moves away from the pads when you pull it, that bearing is pretty much the only thing left to lock it to not free turning.

    The bottom line however is, with the left cover on and the right off, if pulling in the clutch does not push the silver friction plate away from the pads you can 'flower nut' adjusting yourself to death but it will not compensate for an improperly adjusted cable to begin with is all.
     
    #11 KCvale, Sep 10, 2010
    Last edited: Sep 10, 2010
  12. bairdco

    bairdco a guy who makes cool bikes

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    is it just me, or does it seem like there's a lot more clutch problems happening lately?
     
  13. ncfootballchamp

    ncfootballchamp New Member

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    can you guys please give me a picture to go off of because I don't know the terms you're using.

    A picture of what "to wedge against to break that bearings dried grease free"

    Thanks so much
     
  14. GearNut

    GearNut Active Member

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    #14 GearNut, Sep 11, 2010
    Last edited: Sep 11, 2010
  15. ncfootballchamp

    ncfootballchamp New Member

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    Ok thanks but i still don't understand what i'm supposed to be doing. I mean my engine looks a lot like the picture minus all the usage. I can't see any dried grease, except maybe around the edge where the friction plates are
     
  16. KCvale

    KCvale Active Member

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    You can't see the dried grease.
    It is in the Bearing Seam.

    [​IMG]

    The outer part is the clutch pads and gear to the motor.
    The inner part (with the 3 studs) is what the pressure plate mounts over the 3 studs, held in place with the Flower Not, and transfers the drive across to the drive sprocket when they come in contact.

    You break it free as indicated by using 2 of the 3 studs (and not the middle one), and make sure your back wheel is free to move.

    Also note that is the same un-run motor in the first pic, I just took the pic after I had greased it up.
    For those I seemed to have made no sense to with a little grease on the pads, that is what I mean.
    So light a coating on the pads you can't even tell, but a bit of 'limited slip' for when the clutch engages is all.

    Properly adjusted these clutches haven't given me any operation problems.
    It is just when you are not buying brand new motors the grease in that bearing will have dried out and lock up.
     
    #16 KCvale, Sep 11, 2010
    Last edited: Sep 11, 2010
  17. bairdco

    bairdco a guy who makes cool bikes

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    please, please, PLEASE, stop telling people that you put dabs of grease on your clutch pads.

    i understand that you think it works for you, but it is NOT a good idea. anybody who's ever blown a seal in a transmission can tell you what grease does to a dry friction clutch disc. grease will make a clutch slip. it can saturate the pads and ruin them. the clutch pads are supposed to be dry.

    since you won't stop telling people to grease them, i won't stop telling people NOT to.

    here's a FAQ from Centerforce Performance Clutches. (i realize they don't make a clutch disc for our bikes, but it's the same principals involved.)

    WHAT COULD BE THE CAUSES FOR CLUTCH CHATTER?
    #14 Oil Or Grease Contamination On Clutch Facings.

    WHAT COULD BE THE CAUSE FOR IMPROPER CLUTCH RELEASE?
    #18 Oil Or Grease Contamination On Clutch Facings.

    WHAT ARE THE POSSIBLE CAUSES FOR CLUTCH SLIPPAGE?
    #4 Clutch Assembly Contaminated With Grease/Oil

    bottom line, these are DRY FRICTION clutches, and should NEVER have any grease or oil on them.
     
  18. Creative Engineering

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    In addition, it is impossible for dried out grease to lock-up the clutch.

    Look at the 3D animations in this thread and you will see how the clutch works.

    http://motorbicycling.com/f30/animated-view-motorized-bicycle-clutch-assembly-8939.html

    Consider the amount of torque that is being applied to the internal components shown in the exploded view. Dried grease would be no match for the torque at the rear wheel that is transferred through the countershaft.

    On some engines the clutch friction material is a bit gummy and sticky as opposed to the typical hard dry friction material. From the time the engine is assembled, until the end-user installs it...it could be months. Months of sitting there with heavy spring pressure compressing the gummy friction material.

    This will cause the friction material to stick to both the pressure plate and the inner hub.

    It is very rare that it is necessary to free-up the inner hub in order to get the bike to roll. Simply remove the cover, pull the clutch lever, and pop the pressure plate loose with a flat tip screwdriver.

    Now...If you really want to make a BIG difference in your clutch...remove the friction pieces and trim them slightly along the edges so that they float in the gear...not a light press fit. This will give you a positive engagement at both the inner hub and the pressure plate effectively doubling your useable clutch friction surface. This is how the clutch was designed and was intended to work. On most of these engines the friction material is just crammed into the gear.

    Try it on your next build KC...you'll like it! Hint...prior to doing the screwdriver thing in order to free up the dried grease...remove the friction material from the gear first. You will then find that the hub with the three pins spins completely free...dried grease and all.

    Again...refer to the animations...the clutch is incredibly simple.

    Jim
     
    #18 Creative Engineering, Sep 11, 2010
    Last edited: Sep 12, 2010
  19. txlixard469

    txlixard469 New Member

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    ay gear head i hearing some squeeking in my clutch iI put ol in where the sprocket is and the squeeking went away for a bit but returned can u help me out b4 it gets to bad.
     
  20. GearNut

    GearNut Active Member

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    Oil does not belong in the gear case of these engines. You will run a high risk of it getting inside the clutch and contaminating the friction pads. Use a quality high temp grease to lube the gears. Use only a pea sized blob placed right where the gears mesh together. It will spread itself around as you ride. Any more than a pea sized blob will just get things really messy in there really fast and will not lubricate the gears any better.

    Also grease the ball bearing inside the hollow gear shaft and the release arm in the side cover.

    Also, have you lubricated the clutch hub bearings recently?
     

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