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Adjusting throttle cable for snap back

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by acasta, Aug 26, 2013.

  1. I'm getting my bike ready to sell and one of the things I need to fix is the throttle snapping back into place.
    I think i've determined the problem to having too much slack in the return (?) line. There is no adjustment at the grip so I've tried to adjust it at the carb but I don't think I'm getting it. It's a tight space to get the spanners in and I can't get much movement in there.

    I've attached a photo, I believe the top cable is the one I need to adjust. Could someone explain, with words or draw on pic how to tighten this cable?

    Throttle (Medium).
  2. Also check that the throttle grip isn't rubbing on the switch block, causing a slow return.
  3. Is it not returning fast enough or something?
    Have both cables been lubricated?
    I doubt adjusting the return cable will help if the throttle isn't "snapping" back into place fast enough, I'm pretty sure its just there for safety reasons,so you can shut off the fuel if the other cable or carby jams or something.
    The spring should control how fast it snaps back.
  4. #4 RichiB, Aug 28, 2013
    Last edited: Aug 28, 2013
    From Motion Pro Revolver Instructions - it discusses the return cable, I underlined for emphasis.
    Step 4: Cable Adjustments
    The aluminum inline adjusters on the cable housing near the throttle should be closed all way before starting this step. Some motorcycles have threaded adjusters on the throttle body or carb cable mounts. If so, this is where you will start. If there are only slip-on fittings at the carb or throttle bodies, the adjustments will be made at the inline adjusters only. Start with the pull cable and adjust the adjuster until there is approximately 1-2mm of free play in the cable. The throttle should be able to rotate a few degrees before starting to open the carbs or throttle bodies. Once this adjustment is complete, twist the throttle and let go several times. The throttle should snap back closed very quickly. If it does not, double check all of your previous work to determine the
    problem. DO NOT continue until the throttle snaps back quickly on its own once released. Once the pull cable is adjusted, now adjust the return cable. The return cable should have 2-3mm of free play. If you can reach the exposed wire of the return cable at the carbs or throttle bodies, you should be able to deflect it from straight by a millimeter or so if it is adjusted properly. Open the
    throttle and release again and it should snap back as quickly as before. If not, the return cable is too tight. Adjust and operate the throttle again, until it snaps back quickly.

    To tighten a cable, you want to effectively increase the length of housing between the 2 fixed points that hold the housing in place. In your case this means increasing the amount of nut on the housing side, which means unscrewing it from where it is, away from the exposed cable. So unlock the locknut and unscrew the cable adjuster. You can feel the tension on the cable with your finger, its easy to tell which way its working. Then tighten the 2 locknuts again using two spanners with opposing force towards each other, if that makes sense. Check your work. Adjust if necessary until you nail it. Test it before riding at all bar angles just to be sure in case there was a tight spot you didnt know about previously. Done.
  5. You won't be able to adjust that cable as is because there is only one locknut. You would need to add another lock nut on the left side of the bracket so that you can use both to alter the position of the housing. If that doesn't make much sense, just have a look at the bottom cable, which does have two lock nuts.

    However, I'm quite doubtful that adjusting the return cable would fix your throttle stick problem unless it was too tight. Yours is already at it's loosest setting, and I can see that there is free play in it. Consider that your throttle should snap back even if the return cable is disconnected.
  6. Good eyes mate.
  7. If both cables have in line adjusters up near the handlebars, then I have found it best to have the lower adjustment at carb/throttle body to be backed off all the way, and do all of the adjusting at the top in line adjusters or throttle housing adjusters. This is to make it far easier to dismantle throttle housing in order to periodically oil the cables. If the bottom adjusters are screwed out, then you sometimes cannot get enough slack in the cables at the throttle housing to remove them from the throttle tube, and then have to spend alot more time to pull bike apart to get access to bottom adjusters.

    Also, sticking throttle is usually not caused by a loose return cable as others have already said. Dry, rusty, gummed up cables can stick, so run some oil down them, as Wascal has said. Grip rubbing on throttle housing has been mentioned, but the grip can also slip off the end of the throttle tube & rub on the handlebar or bar end. Trim off excess rubber grip with razor. Also the throttle tube itself can stick on the handlebar tubing, so remove throttle housing & cables and see if throttle tube spins freely on handlebar.