Throttle cable Issues

Discussion in 'Motorized Bicycle General Discussion' started by crabdance, Jul 30, 2008.

  1. Norman

    Norman LORD VADER Moderator
    Staff Member

    Joined:
    Jan 16, 2008
    Messages:
    2,605
    Likes Received:
    1
    Re: Throttle hookup

    sounds to me like the throttle is sticking or you have an air leak on the intake manifold. if you tighten the top of the carb too much it can cause the throttle slide to stick you might look at that first. I finger tighten the carbs top the spring inside the slide should allow you to open the throttle wide open and when you let go of the throttle it should snap back shut at least that is the way I've always tried to make mine work. There is a lot to things that can make the throttle stick most are in the twistgrip or at the carbs slide sometimes the cable is bent too much or it has a pinched spot or just needs a little lube.

    for checking for an airleak spray around the intake manifold to cylinder mount and at the carbs slip on mount if you get a change in rpm when you spray the area with carb cleaner you probably have a leak allowing in air. Look at the classic posts for how to deal with these problems. I like to use silicone on the slip joint and a good grade gasket on the manifold mount.
     
    #21 Norman, Oct 13, 2008
    Last edited: Oct 13, 2008
  2. bigdreamz2000

    bigdreamz2000 New Member

    Joined:
    Oct 8, 2008
    Messages:
    35
    Likes Received:
    0
    Re: Throttle hookup

    Good info, can't wait to get home and try that out.
     
  3. PublicMember

    PublicMember New Member

    Joined:
    Oct 16, 2008
    Messages:
    12
    Likes Received:
    0
    Hi, I'm new to this motorized bike thing and I bought a kit online and I've been having trouble with the throttle. It seems that i have everything hooked up right but there is no slack on the cable so when it's put on I can't turn it more than a smidgen. What could be the problem? I don't want this throttle thing to ruin my almost finished project.
     
  4. HoughMade

    HoughMade New Member

    Joined:
    Apr 15, 2008
    Messages:
    624
    Likes Received:
    1
    Re: Throttle trouble.

    A few questions-

    W-ith the throttle disconnected, does the cable move easily in and out of the sheath when you twist it?

    Does the throttle itself move freely with the cable disconnected?

    Is the cable truly too short? Do you have to pull hard on the cable to get it to reach to where it connects?

    Of course, pics would be great, but we'll see what we can do with a bit more info.
     
  5. PublicMember

    PublicMember New Member

    Joined:
    Oct 16, 2008
    Messages:
    12
    Likes Received:
    0
    Re: Throttle trouble.

    I'm having some trouble getting a picture into a post but it's of the part that goes into the carb and the throttle handle. The spring is compressed pretty much all the way and the throttle is in the neutral position.
     
  6. i-paint

    i-paint New Member

    Joined:
    May 24, 2008
    Messages:
    136
    Likes Received:
    1
    Re: Throttle trouble.

    Maybe the slide, the round part that goes down in the carb isn't seated. It has to be turned toa certain position to go all the way down. The narrow slot goes to the outside of the carburetor opposite the idle screw. The short wider slot goes over the idle screw.
     
  7. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    4
    Re: Throttle trouble.

    I don't think your slide is going down all the way.
    Sometimes you have to gently sand the slide to fit. If it is sticking, use some 400 grit wet-or-dry and light oil or water and make a tube with the paper and turn the slide in it and keep checking until it fits.
     
  8. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    4
    Re: Throttle trouble.

    Also, screw the adjuster at the top of the carb in and the adjuster at the throttle grip in until you have a little slack in the cable.
     
  9. PublicMember

    PublicMember New Member

    Joined:
    Oct 16, 2008
    Messages:
    12
    Likes Received:
    0
    Re: Throttle trouble.

    http://i266.photobucket.com/albums/ii267/PublicMember/DSCF0720.jpg

    If the cylinder at the end that the pin is coming out of is the slide you are talking about it will sit at the bottom when the throttle cable isn't hooked up to the handle. I have to pull the cable hard to get it to hook up to the handle.
     
  10. PublicMember

    PublicMember New Member

    Joined:
    Oct 16, 2008
    Messages:
    12
    Likes Received:
    0
    Re: Throttle trouble.

    So should I just buy a new throttle cable or handle or something?
     
  11. jburr36

    jburr36 Member

    Joined:
    Jul 17, 2008
    Messages:
    284
    Likes Received:
    0
    Re: Throttle trouble.

    It appears that your cable sheath is too long making the cable too short. I would try to trim the sheath about 1/2 inch. What I did is to pry the metal end on the sheath off without damaging it and stripped some of the plastic off of the steel coil. Then I used a sharp knife to bend the top of the coil out just enough to grab onto it with needle nose pliers and unwrapped it to my specified length. When done I slid that metal end cap back on the sheath.
     
  12. PublicMember

    PublicMember New Member

    Joined:
    Oct 16, 2008
    Messages:
    12
    Likes Received:
    0
    Re: Throttle trouble.

    That sounds like it should work, i'll give it a try when i get back from class.
     
  13. i-paint

    i-paint New Member

    Joined:
    May 24, 2008
    Messages:
    136
    Likes Received:
    1
    Re: Throttle trouble.

    Hi, I can't tell from the picture but do you have the spring between the slide and the throttle cap?
     
  14. PublicMember

    PublicMember New Member

    Joined:
    Oct 16, 2008
    Messages:
    12
    Likes Received:
    0
    Re: Throttle trouble.

    Yes, the spring is in there but it is compressed all the way when the throttle cable is connected to the handle.
     
  15. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    4
    Re: Throttle trouble.

    Alternately, you can remove the cable from the housing, and cut the cable housing with a bench grider, dremel tool, or cut off saw. Make sure to dress the inside of it so it doesn't snag or cut the cable.
     
  16. PublicMember

    PublicMember New Member

    Joined:
    Oct 16, 2008
    Messages:
    12
    Likes Received:
    0
    Re: Throttle trouble.

    I couldn't get the end of the outer cable off so I ended up taking a chunk out of the middle. I think I took out too much but the throttle feels better when I turn it. I put it back together with tape and I made it so it is fairly straight but it isn't completely smooth on the inside but it isn't snagging so I think it should work. Now I just need to shorten the chain and get some fuel and try it out.
     
  17. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Joined:
    Jan 8, 2008
    Messages:
    11,529
    Likes Received:
    4
    Re: Throttle trouble.

    Keep us posted.
     
  18. old motorbike

    old motorbike New Member

    Joined:
    Sep 21, 2008
    Messages:
    352
    Likes Received:
    0
    Re: Throttle trouble.

    There was a stop in the throttle control on mine that I had to cut out to get enough of a turn to have enough cable movement.
     
  19. chadmashman

    chadmashman New Member

    Joined:
    Oct 26, 2008
    Messages:
    3
    Likes Received:
    0
    I just put a RAW 49cc motor from zone8cycling on a Schwinn OCC. Starts up fine, but when I twist the throttle, it doesn't seem to change the speed, it's running me at about 15mph without doing anything to the throttle. If I engage the clutch, the motor takes off super fast. I even broke the plastic part that holds the end of the cable on two throttles now turning to too hard thinking it wasn't working. Any ideas?

    Also, which way turning the carb adjustment screw will decrease the idle speed?

    Thanks

    Chad
     
  20. mchln

    mchln New Member

    Joined:
    Oct 26, 2008
    Messages:
    1
    Likes Received:
    0
    Re: Throttle useless

    well i just finished my kulana moondog and I had the same problem. it would run 15 mph and i am not even twisting the throttle. when I squeeze on the clutch to let it idle it would race and I would have to shut it down. I took the throttle apart and it turned out that the cable end on the twist throttle was not resting on the stopper meaning all the way down without any tension on the cable. The finish of the plastic twist throttle was so cheap that it was stuck in the middle position when I installed it initially. So it was as if the throttle was half way open already. when I examined it, i reinstalled it and got it on right. Now my bike is almost too slow at idle. So try a closer look at your throttle assembly cuz it might be the same problem as mine. by the way idle adjuster, decreases to the left, increases to the right. I am going to order another throttle hopefully it will be a better unit than the one that came with my kit. hope this helps.
     

Share This Page