I've created a monster...leave the internal clutch spring alone!

Discussion in 'Motorized Bicycle General Discussion' started by Creative Engineering, Jun 14, 2009.

  1. Creative Engineering

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    Guys,

    I've seen a lot of posts lately regarding the adjustment of the main clutch spring.

    I had one engine last year that had a REALLY tight clutch, (At the lever), due to the fact that during assembly the Chinese ran the preload nut down too tight!

    I posted a thread on "how to" remedy this problem...external adjustment of the primary clutch spring dated 11/30/08

    99.9% of the time; this adjustment is fine from the factory!

    The spring is a high rate spring, which means that very little adjustment is needed to correct for a slipping clutch, or one that is excessively tight. 1/2 - 1 turn is usually all that is needed!

    It is important that the spring rate is set correctly...and again 99.9% of the time it's right from the factory.

    Norman did a good job of expanding on my original post, but this IS NOT something that should be messed with in general.

    I posted this information to help out those who had clutch problems beyond the normal.

    If you have broken a clutch lever or cable, it will help to loosen the tension on the spring.

    If you have added a tuned pipe, or other performance mod...you may need to tighten the pre-load a bit.

    Use good judgement...adjusting the tension of this spring should not be done until you have a full knowledge of the clutch assembly in these engines.

    Jim
     
  2. reg454

    reg454 New Member

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    good info Maniac
     
  3. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Yes, read my signature.
     
  4. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Absolutely - I even feel bad for asking earlier. And I ended up not needing to mess with mine (yet :) ) Tighter is not necessarily better.

    "...........(nothing should)..... be done until you have a full knowledge of the clutch assembly in these engines." AMEN. I recently found out how few people have a FULL understanding of how this clutch works (self included)


    I think the easiest GOOD thing you can do AFTER you've done all the external clutch adjustments is to assure the clutch pads float FREELY in the "holes" - because if these ain't happenin' you ain't got but half-a-clutch! It's so easy to do and makes such a HUGE difference, it really should be one of those new bike check things....
     
    #4 Pablo, Jun 15, 2009
    Last edited: Jun 15, 2009
  5. matt167

    matt167 New Member

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    I'm certinly not going to do anything to my bike until I actully get it running.. got the master links I ordered the other day, hooked up the spring tensioner, hooked everything else and did a test by walking the bike with the clutch disingauged and finally the chain never popped off the sprocket.. took it for another test run, thinking I might have actully had it right, and it came to a tire screeching halt... chain had slapped togther ( I really need a 1 link replaced with a 1/2 link ) and caused it to jump off. chain tensioner got pulled outward and mangled when the chain wound around the inside of the spokes.. can't be good for the engine, but it's still holding togther
     
  6. 2door

    2door Moderator
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    Jim,
    Ya gotta be careful with suggestions to the great unwashed. They can be taken wrong, or at least applied wrong. Remember who is reading what you write.
    Tom


    Matt,
    Any chain tensioner be they spring type or rigid need to be secured to the bike frame. The kit supplied clamp-on tensioner brackets are notorious for loosening and rotating into the spokes. I see some of the new brackets now come with two bolts but even so I would not trust a clamp-on installation of this critical item. Some of the guys use a self tapping screw through the bracket into the chainstay, I drill completely through and use a 10/32 bolt and nut. Either way you're assured of a tensioner that will stay put and not cause you expensive and possibly dangerous problems. Hope this helps.
    Tom
     
  7. matt167

    matt167 New Member

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    I'm tossing the stock tensioner and the spring tensioner that got mangled. and I'v got a TSC tensioner coming I'm going to use only for the wheel, the rest will be like you did mounting the bar along between the 2 bars and putting a slot in it for adjustment.. I can't weld that good with a wire feed, but I'm going to use quick steel epoxy over my welds to ensure they stay put... I'v had a stock tensioner get pulled in and a spring tensioner get pulled out, so I'm not going to risk anything else.
    on the bike that the rear wheel got messed up on, I didn't realise the clutch cable went thru the hole on the adjuster, and I had a HD zip tie holding it to the seat tube.. wasn't until the bike it's on now that I realised that's where it goes..
    in any case, my clutch seems to be working like it should..
     
  8. BrettMavriK

    BrettMavriK New Member

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    I can't help it, but I have to reply to this thread.
    You are kinda' contradicting yourself here, Jim.....

    "Leave The Internal Clutch Spring Adjustment Alone!"
    BUT it's okay to adjust it if:
    -You have a really tight clutch because it was overtightened from the factory
    -You have a slipping clutch
    -You broke off the lever


    In my opinion, it is the FIRST thing that should be adjusted, as all other adjustments will need to be made after this adjustment like a domino effect. By saying this, Jim, you are getting MB'ers to fear what's in there, and not mess with it. It's a spring guys, with a nut for a seat on one side that can be turned to make the spring more stiff or more soft. Most think the flower nut is where it's at as far as adjustment, and this couldn't be further from the truth. All the flower nut is supposed to do is "snug" the gear plate to the clutch pads and take up the slack. By squashing the flower nut down real tight all you are doing is stressing the clutch pads and effectively shortening the "throw" of the clutch lever. It is not meant to adjust the spring load of the clutch. The Spring Itself IS. Using the flower nut as an adjustment point is a "band-aid" adjustment.

    After having prolonged clutch problems to where I even changed the friction material to carbonite, I decided to Adjust the internal clutch spring. Bingo! Fixed.
    I wish I would have done it way earlier as it would've saved me a big load of time and grief.

    What's the worst that can happen if anyone over adjusts the clutch spring one way or the other???
    -The clutch slips and they go nowhere
    -The clutch won't release and they have to readjust. If they decide to go riding with a clutch that won't release (not using common sense) brakes and a kill switch will overcome the motor.

    If you're having clutch problems, the Clutch Spring Adjustment should be the First place you should look. All other adjustments fall after "The Most Important Adjustment" like you said.
    I like the post Norm had done showing the guts of the clutch. It helps people to understand.

    I think did a nice, helpful write up on Adjusting The Clutch after my experience
    which prompted me to learn:

    Happy Time Clutch Adjustment

    The adjustment of the clutch on these engines is a magical ballet between a few factors:
    1. Flower nut depth/tension
    2. Internal Clutch Spring Tension (which actually is adjustable externally and is the most important)
    3. Thickness of the clutch material
    4. Pin Length

    When one thing changes, everything else has to be adjusted.

    The Internal Clutch Spring Tension can be adjusted by removing the clutch cable stanchion from the block, taking a 3/16" steel dowel and inserting it into the hole to find one of the four square notches on the internal spring adjustment nut inside to lock it, and spinning the motor (with the spark plug wire off) to tighten or loosen. Running the engine backwards tightens the internal spring; running the engine forward loosens it. Another problem I can see by design, is that there is nothing to "lock" this adjustment in place once the adjustment is made on the internal spring tension; meaning, it could "float" upon operation of the motor by vibration either to tighten or loosen....I bet on the latter.


    Take calipers and measure the thickness of a couple of your clutch pads.
    Find a measurement from a new set of pads. Are your pads "mushroomed"
    and/ or deformed at all ?

    Like I said, it's a ballet,
    So start by tightening the internal spring a bit. (Back off the flower nut first by holding in the clutch lever to release the pressure) Remove the cable from the arm and stanchion from the block and go to work.
    A good start is 1 revolution backwards to tighten the spring. I had to tighten mine by 4 revolutions, so results may vary depending on what Hong Kong Phooey decided to tighten yours at or if it loosened by vibration.
    -Then snug up the flower nut not too tight, by holding in the clutch lever in after the Stanchion and cable are reinstalled.

    Remember: Every Time the Flower Nut Is Adjusted , The Cable-To-Clutch Arm Set Screw Must Be Reset

    And lastly, loosen the clutch actuator housing screws and notice if the pin pushes the housing out. If so, take note of the gap where it stops pushing between the actuator housing and the block. This determines that the pin is now too long and will need to be shortened just under the amount of this gap. Just make sure the actuator housing gap is parallel to the block top to bottom, left to right to determine more accurately how much the pin needs to be shortened. Just play with the three screws on the housing and go by feel. You will know when you got pin length right when there is ever so slight of and outward push from the pin to the actuator housing just before the housing snugs up to the block.

    Now, if after all of this the housing doesn't push out at all, or the arm has to swing waaaaay in to operate, or doesn't operate at all. Then you have the opposite...The Pin Is Too Short, or the clutch pads have worn so thin that they are out of useable adjustment spec.

    (watch out for that ball bearing behind the pin that likes to fall out and roll under your work bench)

    Then the ballet begins between the flower nut, arm-to-cable set screw point, and feel.

    I like it where the cable is set just off of where the arm starts to tighten when turned. A good tip is to leave the cable housing "adjuster screws" at the lever midway, and at the stanchion all the way in. This allows you to dial it in and fine tune it to exactly where you want. Bringing out the cable housing adjuster at the stanchion tightens the cable without having to dilly-dally with the cable set screw at the arm, and can provide a more minute ( my'noot ) (SP?) adjustment.

    HTH
    'BrettMavriK



    Not to step on toes here, but I felt it important to respond to this post.

    'BrettMavriK


     
    #8 BrettMavriK, Jun 16, 2009
    Last edited: Jun 16, 2009
  9. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Awesome post Brett. No one is "wrong" here - just all good information. Jim did write ""...........(nothing should)..... be done until you have a full knowledge of the clutch assembly in these engines." AND You have clearly demostrated you have full knowledge and with the sharing of both of you - most all people reading should have gained light years of knowledge. .flg.dance1
     
  10. BrettMavriK

    BrettMavriK New Member

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    I agree wholeheartedly, Pablo...

    Everyone has an opinion, and most are just trying to help others from their experiences.
    The hardest part of writing as opposed to speaking in person is the absence of connotation, inflection, and attitude connected to the writing. It's very easy to take things out of intended context and get offended. It sometimes leaves one with a bad taste and refraining from wanting to respond to things in the future.
    I try to keep an open mind as best I can. Eventually, everything always finds balance.

    'BrettMavriK


     
  11. reg454

    reg454 New Member

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    This is all good information and should be required reading for new people.
    Their should be a new thread started on the main page that says required reading for new people. And have a but load of information put together with the simple problems they could see and then go into detail about how to solve them and other suggestions for them. The wealth of information on the site is great but should be pulled into a new thread for easy findings.
     
  12. Creative Engineering

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    I remember that post Brett...and it is good! It is a very thorough description.

    I know this thread seems contradictory, it's just that I had originally mentioned this as a possible solution to an excessively tight clutch.

    Last fall I saw several threads where guys were breaking thier clutch cables and or the clutch lever.

    One of the engines I had here was really tight due to the fact that the internal adjustment nut had been set way too tight at the factory. I think this is more of a rarity than the norm.

    Pics are great, but I think a CAD generated animation is in order. I'll see if I can post something this evening.

    If I can pull it off; it will offer the most detailed visual explanation possible and should be a benefit to the forum for a long time to come.

    Does anyone know if you can add animated gifs to a post?

    Jim
     
  13. NunyaBidness

    NunyaBidness Active Member

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    Seeing as how some of the emoticons seem to be animated gif's I don't see why it would be a problem.
    .shft.
     
  14. Dave31

    Dave31 Moderator
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    Yes you can Jim, I use my photobucket to host the gifs and then copy and past the IMG code

    [​IMG]

    [​IMG]

    [​IMG]
     
  15. BrettMavriK

    BrettMavriK New Member

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    Nice Solution!

    That isn't going anywhere, and it even protects the paint.

    'BrettMavriK
     
  16. Creative Engineering

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    Thanks fair...I tested it this afternoon, (through photobucket), and the resolution was far better than I had expected.

    I've got 2 finished...3 to go.

    Thank you!

    Jim
     

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