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Freeplay in throttle

Discussion in 'Technical and Troubleshooting Torque' started by fupo1, Nov 15, 2013.

  1. Hey guys
    When I got my bike (second hand) there was about 1cm freeplay in the throttle it was annoying me :sick:

    Anyone know if this is normal? Did not notice it mentioned in the manual (Yamaha FZ6r) so hoping can get some help here.

    I took the covers off the bike and noticed the slack in the cable at the throttle body. I adjusted it (took away the slack) and now have almost nil freeplay in the throttle.


    But when I go full throttle in Neutral it sometimes almost stalls. Only sometimes happens - a split second sounds like it will stall, but never actually stalls and engine runs smooth again. Because of this have been wary not to full throttle when riding, IE not in neutral.

    I have checked and the throttle cable is aligned and looks fine, does not look slipping at the throttle body end. I only adjusted it from the throttle body end, not the handlebar end.
  2. Your owners manual should probably have the specification for throttle free travel. A couple of mm would be typical. With the bike idling turn the handlebars from lock to lock and if there is any change in idle speed, you have insufficient free travel. I'm not really able to understand the behaviour you are describing though, do you mean it sort of dies a bit instead of revving right up?
    • Like Like x 1
  3. Thanks I will look again in the manual but did not find it before.
    Exactly like you said, the engine sort of dies before revving up.
  4. In a carbied bike that suggests not enough fuel ie slightly lean idle mixture. In a FI bike the throttle position sensor might need adjusting. Some bikes you can do it yourself, others require the right tool to interrogate the ECM.
    For other DIY solutions, make sure there's no loose clamps on the throttle bodies or any hoses off their attachment points letting air in where it shouldn't be. Also check connectors for the sensors are clean and tight. You could also have dirty fuel, dirty injectors/jets or dirty plugs. It's a bit of a crap shoot trying to diagnose stuff from a short block of text.
    • Like Like x 1
  5. Everything is tight I double checked. I think it may be the fuel thanks. I will get some new fuel and see how it goes, hope that it is. But it was not happening before I tightened the slack in the throttle cable and was on the same tank of fuel. I will have to do a few more test rides and see, been raining lately so I have not been out on the road far.
  6. Did you remove TOO MUCH slack from the throttle?

    When closed, a throttle isn't actually closed all the way typically.

    Have you considered "undoing" the change you made and see if the throttle closed behaviour returns to normal?
  7. A little bit of freeplay (couple of mm) is normal, as said above. I agree you should try feeding a little bit back in and see what happens.
  8. For my FZ6S the free-play (spec) is 3-5 mm.
  9. Thanks for all the suggestions. Glad to know a few mm freeplay is usual. I will change the fuel, give it a good warm up and see how it goes. If it still feels wrong I will take it apart again to adjust more slack to the throttle cable.(y)