out of control throttle

Discussion in 'General Questions' started by warriorairman, Oct 24, 2014.

  1. warriorairman

    warriorairman New Member

    I put a new 88cc china girl in my road bike it runs great but I I have no throttle response; the engine runs wide open and now matter hiw I turn the throttle it doesn't change anything

  2. crassius

    crassius Well-Known Member

    most likely the slide is in backwards, but cable should be checked & air leaks should also be checked

    in rare cases, the throttle cable inner is just too short, but that can be fixed by trimming just 1/8 inch off the plastic holder on the grip
  3. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    I deal with these kind of problems with my customers fairly often.

    Did you attach the throttle cable to the carb?

    Take carb off the intake and look to see that the slide goes all the way down and springs back all the way up.

    Of course the idle screw holds the slide up a little from the bottom.

    Also check that there is an O ring in the carb sealing it to the intake or use some kind of goop to seal.

    Just had a guy that put the slide in backwards so that the little pin in the carb was holding it up.
    The slot on the side of the slide aligns with the pin.

    Simple stuff to diagnose.........

    PS: It's a 66 cc and I presume you have an NT type carb.
  4. KCvale

    KCvale Motorized Bicycle Vendor

    Hi Warrior, welcome.
    Just for your info you have a 66cc 2-stroke engine and whatever marketing claims you read are BS.
    Chances are you have the NT carb and it's easy.

    Pull the air cleaner off and look inside as you twist the throttle.
    The grey barrel inside should go up and out of the air passage at full throttle, then let go of the throttle.
    The retaining spring slams that grey barrel down to the idle set screw leaving just a touch of room for airflow at idle.

    If not you know where to look.
    There are cable length adjuster at each end of the throttle, they both have retaining nuts, pull the one off of the NT's cable nipple, that a couple mills right there.
    On the throttle itself the L tube can be screwed in as well as it's cable adjuster retaining nut.

    Cables have 2 parts...
    The actual metal cable itself, and the outer sheath, it's the sheath that determines the cable end length, and it's adjustable.
  5. piecepatrol99

    piecepatrol99 Member

    Hi Warrior. Welcome to the insanity.

    I have a 49cc 2stroke. I had a similiar problem with my clutch cable. A bur inside the sheath was causing the cable to stick. The lever pulled in, but when I released it, the clutch would still slip no matter what I did to adjust it.
    The problem wasn't completely fixed until it completely broke. The bur frayed the cable til strands broke and jammed the cable effectively disengaging the clutch.
    I took it apart, stripped the broken strands and reassembled it. I was 15 miles from home, just got off work in a lumber yard and was in no mood to pedal home.

    Just something else to check along with the possible stuck carb slide and air leaks.
    Also check the head gasket. Anything loose from the carb to the exhaust port can cause a high idle.

    Hope you ger her running right soon.