bike shaking badly at low speeds

Discussion in '2-Stroke Engines' started by JosephGarcia, Apr 21, 2007.

  1. JosephGarcia

    JosephGarcia Guest

    runs fine when going over 8MPh any slower, and the bike starts shaking badly, and pulling me ahead in short jerks, if i pull in the clutch it runs fine,so i know its not the engine. its somewhere in the chain, but i cant tell where!!! i adjusted everything, and the chain moves pretty smoothly, sprockets are aligned, i cant find out the problem!!!!!

    Bike is rideable, but I feel like its falling apart when i go slow.
     

  2. jeffspeeder

    jeffspeeder Guest

    i had the experience to with that it is the motor cuz you know it you go slow enough the bike will stall. its going slow almost to the point whare it is about to stall is what its doing its giveing it gas but misfireing alot. i dont usually go under 10 - 15 mph without pushing the cluch cuz mine will shake to
     
  3. nms

    nms Guest

    In a car that is a sign you need to downshift to a lower gear or pull in the clutch. Since you can't switch gears, I would guess the answer is pull the clutch and coast.

    What size is your driven sprocket? 36, 44, 50 teeth? The more teeth the slower you will be able to go without "lugging" the engine, as it's called, but the slower your top speed will be.

    I would guess that this is not unusual, but can't say for sure since I've never operated a motored bike. ;-)

    Hope this helps,
    nms
     
  4. JosephGarcia

    JosephGarcia Guest

    My bike always gave me smooth power even at 3MPh, I never had this happen before. So you guys are saying its misfiring? I should get a new spark plug?
     
  5. jeffspeeder

    jeffspeeder Guest


    tell you the truth im really impreassed that it can do 3mph with the clutch disengaged. mine would never do that. if your bike is running and idleing good and it dose not sound like its misfireing then the spark plug should be good. im saying is these motors dont have an automatic clutch its like in a car if you go to slow with a manual clutch it will stall without pushing the clutch in. so thats what im saying going to slow on the bike is makeing the motor turn over slower then normal.
     
  6. Guest

    Guest Guest

    You're just going too slow.
    Minimum speed is 10 mph.
     
  7. JosephGarcia

    JosephGarcia Guest

    since I got it, it pushed me along at very slow speeds incredibly smoothly, I thought it was normal. I only pulled the clutch when I came to a complete stop. Well I got a replacement sparkplug and I see way better performance and start up, but it still kinda shutters at low speeds. Guess I have to deal with it now, huh?

    I guess good things don't last forever. lol
     
  8. Guest

    Guest Guest

    Be happy it will run at that low of a speed.

    10 MPH is a good speed to call a "low speed limit''.
     
  9. rcjunkie

    rcjunkie Guest

    Actually minimum speed is whatever the engine will tolerate, i.e. bucking. For some it can be as little as 3mph and others it can be higher.

    I personally can putz aroun day long at 3-4 mph but that's because I usually run a 48-50 tooth size sprocket. On my 44 tooth sprocket bike, 8-10 mph is as low as it can go before it bucks.
     
  10. gone_fishin

    gone_fishin Guest

    mine will pull me along level even during warm-up idle, rcjunkie's right, it's whatever the engine can keep on doing...so i'll take a wild stab:

    is it something as simple as idle adjustment, or debris in the carb?

    are you using an inline fuel filter?
     
  11. JosephGarcia

    JosephGarcia Guest

    or course, The previous owner used a filter from day one, and I have been too.

    I posted a reply on this thread the other day where I said I bought a new spark plug and it was still doing the same thing.

    Well I guess everything kinda settled down in the 40 or so miles I rode it since, as It's shaking way less now, Feels a lot smoother.

    On that note, do new sparkplugs have a "break in" in period where they begin to perform better?
     
  12. Guest

    Guest Guest

    Never heard of a plug "breaking in". Maybe you had some crud in the fuel system that worked it's way through? Bad gas?
     
  13. Alson

    Alson Member

    Jerking at low speed

    I have a 44t gear, and a 66cc engine. Mine jerks more now, when I put a expansion chamber on it, if I lower the ideal it jerks less but sometimes dies at idel, so I raise the ideal and it jerks more. So I believe I just have to live with it, it runs good
     
  14. Alson

    Alson Member

    Jerking at low speed

    Oh ya, One time my float was off and I was getting to much gas and it jerked alot. I poted in on a form and Steve told me it sounded like my float. He told me to set it 21mm, and it corected the problem. Look up Carb tuning
     
  15. Jaidous

    Jaidous New Member

    Mine too. I put a new chain on and now it jerks like it's locking up when I accelerate from low speeds. It rolls smooth with clutch engaged. I believe it could be a bearing on the drive shaft. My bikes been through some rough breaksdowns and lock ups. Poor thing.
     
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