Clutch techniques/fine tuning

Discussion in 'Motorized Bicycle General Discussion' started by SavageBlunts904, Jun 4, 2012.

  1. SavageBlunts904

    SavageBlunts904 New Member

    Joined:
    May 9, 2012
    Messages:
    71
    Likes Received:
    0
    OKay so here it is. I am almost done breaking in my lil BGF 49cc and im noticing that my clutch at slow speeds is hopping a little. Jumping the bike alot. When i press the clutch level just a hare it stops and works beautifuly.

    Why is this happening. Is there a way to use the clutch at lower speeds or do i just need a slight adjustment. I would like the clutch to work this way every time i release it. At medium speeds it works fine but like i said at a slower speed 5-15 it hops some. I want this to stop. Help me please.

    Also i do not use a tensioner and this hopping is making me adjust the rear wheel too much. I used it on the other side to match the drive chain and not have a chance to get a spoke kill shot >.< . If that helps at all.

    cvlt1
     
  2. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    5-15? Sounds like you are just slowing down too much before you pull in the clutch.
     
  3. SavageBlunts904

    SavageBlunts904 New Member

    Joined:
    May 9, 2012
    Messages:
    71
    Likes Received:
    0
    I pull in the clutch after i get to the top speed im going to go since im breakin in the motor still. its when im starting off that it jumps. accelerating from 5-15 its jumpy unless i go almost wot.

    but if i hold the clutch level just a little bit while accelerating it doesnt jump one bit. smooth rollin then up at speed i let it go.
     
    #3 SavageBlunts904, Jun 4, 2012
    Last edited: Jun 4, 2012
  4. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    O.K., let go at this from a different angle...pedal a little faster before you dump the clutch, also, not sure what carb you have, but you may want to enrichen the low end mixture if you can.
     
  5. SavageBlunts904

    SavageBlunts904 New Member

    Joined:
    May 9, 2012
    Messages:
    71
    Likes Received:
    0
    Okay. i do normally start the motor with a quick jump then pedal for a few mins to let the motor warm up. i dont just release from a stand still.

    I am running a CNS V3 with a NT needle. Wanted to be able to change the Clip on the needle since the CNS v3 comes with only one notch on the needle. I am using the CNS on a short intake tube not that useless Z tube.
     
  6. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    O.k.
    .
    .
    .
    .
     
  7. SavageBlunts904

    SavageBlunts904 New Member

    Joined:
    May 9, 2012
    Messages:
    71
    Likes Received:
    0
    i need more detials added on to what im trying to master. Thanks in advance to all you just getting on. Thanks bikeguy joe but im looking for a different angle than what you are describing. It says im a newbie but im no ordinary noob to this. I have all the basic info you can read w/o searching through hundreds of forums mastered. Assembly is a cake walk. just the super technical part is what im looking for. If any one can help i'd really appreciate it!
     
  8. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    I will watch this one with much interest.

    Just to be sure, this IS a regular clutch, right? Or is it a centrifugal?

    Or am I just totally misunderstanding what's going on here?
     
  9. SavageBlunts904

    SavageBlunts904 New Member

    Joined:
    May 9, 2012
    Messages:
    71
    Likes Received:
    0
    i think so. its just a regular BGF 49cc.

    After i am going with the motor idling to warm up i let out the clutch very slowly like a motorcycle and if i release it all the way it jumps alot. if i keep it just a little bit from full clutch release it works perfectly. when i release the level fully is when its jumping. I am trying to find a way to tune it so there is no jumping when i release it fully.

    with slow speeds i have no jumps if i hold the handle just a little bit. but if i release all the way it jumps like crazy. which ofc wears on everything

    let me add that i am using a cns v3 carb from a china girl 48 cc. and the exhaust from it as well. the bgf has to have the extra wide crank for any chance of clearance without bending the pipe. even the smaller china exhaust hits the crank.
     
    #9 SavageBlunts904, Jun 4, 2012
    Last edited: Jun 4, 2012
  10. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    Well, you've got me totally stumped, unless it's a running problem, and pulling the clutch a little just allows it to slip enough it smooths out...

    Let's see what the experts have to say. :)
     
  11. 2door

    2door Moderator
    Staff Member

    Joined:
    Sep 15, 2008
    Messages:
    16,301
    Likes Received:
    25
    You still haven't told us how fast you're going before releasing the clutch. Anything less than about ten mph and you're going to have trouble like you're describing. We always suggest to get the bike up to at least 10mph before engaging the clutch to start and when slowing to disengage the clutch.
    Did you ever drive a car with a standard transmission? It's the same thing except you can't downshift to a lower gear for slow speeds. Imagine leaving the car in 4th gear and trying to slow to a crawl with the clutch out (engaged)...same thing.
    Depending on your rear sprocket size "jumping" might occure at slower or faster speeds. Few 2 stroke bikes with a manual clutch will putt along smoothly at less than 10mph, with clutch engaged.

    Tom
     
    #11 2door, Jun 4, 2012
    Last edited: Jun 4, 2012
  12. locell

    locell New Member

    Joined:
    Jan 16, 2010
    Messages:
    215
    Likes Received:
    0
    Did this problem just appear or has it always been like this? I need to get mine to 5-7 mph before I let the clutch out or it will sputter ans just stop. It has always been like this, that's how they work
     
  13. houseofreggae

    houseofreggae New Member

    Joined:
    May 22, 2012
    Messages:
    15
    Likes Received:
    0
    maybe low rpm? try turning your idle screw up a turn or two.
     
  14. SavageBlunts904

    SavageBlunts904 New Member

    Joined:
    May 9, 2012
    Messages:
    71
    Likes Received:
    0
    im am basically asking how to tune the clutch so i can manually use the clutch to smooth **** at every gear. I s there any way i can manually treat any of tese clutches like a standard 4 speed tranny. Being fully capably of driving any manual device there is known to driving. from high weight cranes and forklifsts. and anything in between. Can me manually controlling the clutch adversley affect these stuck a$% clutches.
    My main focus is asking any very experienced motorcycle enthusiasts if i can controll the clutch of this like any manual car out there. I can easily repair any piece of the standard bike kit motors. I need to know if i can keep it slippery to gain smoothness without any long term consequences. Added info. every other piece of my first build is 100% solid. I ddnt expare any expense making this. Thanks for the feedback
    es
    '
     
  15. Pilotgeek

    Pilotgeek New Member

    Joined:
    Apr 6, 2011
    Messages:
    403
    Likes Received:
    0
    You could maybe get a clutch handle with a different pull rate to engage it slower. Under 10mph, my bike jerks a bit. If you're at low idle speed with the clutch out, that's pretty much how it's going to be. These are not motorcycles; the stock kits only have one speed, and that speed is a compromise. Anything under 10mph is pedalling speed, anything over that is for the engine. You said 5-15 in your first post. These engines are not geared to run at 5mph; it's going to be fighting to stay running at that speed. If you want to have a smooth engine at those speeds, get a larger rear sprocket.
     
  16. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    I just want to know what the **** he is talking about now...
     
  17. kolomootro

    kolomootro New Member

    Joined:
    May 24, 2011
    Messages:
    62
    Likes Received:
    0
    maybe its running rich at slow speed....just a suggestion
     
  18. killercanuck

    killercanuck New Member

    Joined:
    Dec 17, 2009
    Messages:
    1,749
    Likes Received:
    0
    At lower speeds ht's will pulse and jerk a bit, that sounds like what he's having. Like when you're going too slow and it jerks till you get going a better speed. I think that's what he's talking about.

    So if it doesn't do it when you pull your clutch lever a hair and it goes away, then pull your clutch lever a hair :p

    You gotta remember SavageB, its still breaking in, and your clutch pads will settle some after some riding time. But you can give this a read through to give you a better idea about what you can and can't adjust clutch wise:

    http://motorbicycling.com/showthread.php?t=22726

    gl.
     
    #18 killercanuck, Jun 5, 2012
    Last edited: Jun 5, 2012
  19. biknut

    biknut Active Member

    Joined:
    Sep 28, 2010
    Messages:
    6,365
    Likes Received:
    3
    If it doesn't do it at 15 mph and up, my guess is it's chain snatch. It's caused by going too slow with clutch engaged. My bike does it at about 11 mph and lower.
     
  20. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    1
    I made the suggestion that it was being operated too slow....he thinks it's something else.

    What, I do not know.
     

Share This Page