My bike's rpm increases after a short ride of 5 kms such that it moves forward even if the throttle is in its resting state. I know there is a throttle movement adjusting nut but not sure should I adjust the freeplay of the throttle or should I decrease the rpm using the carburettor idling speed adjusting screw. Its a 125 cc honda shine bike.

  • Do you know the rpm at idle?
    – raydowe
    Nov 3 '17 at 8:25
  • Take it to someone who knows...
    – Solar Mike
    Nov 3 '17 at 8:30
  • I think the accelerator cable is caput. common issue .. Sometimes, if you turn the handlebar to the extreme left or right the bike will throttle up.
    – Shobin P
    Nov 3 '17 at 9:41
  • So, you are saying the idle is normal until the engine gets completely warmed up. Is that correct?
    – CharlieRB
    Nov 3 '17 at 12:40
  • that's correct.
    – DhKo
    Nov 3 '17 at 14:33

You should:

1) check the freeplay is correct - if it is holding the throttle open then adjusting the idle screw on the carburettor won't do much.

2) if the freeplay is correct then is the idle speed correct?

3) adjust idle speed as or if necessary.


Check the carburetor: inside there is a cylinder with a spring attached: shut the fuel off remove the two bolts carefully . one on each side of the carburetor. On the top of the carburetor there is a cap. Unscrew it carefully slide out the cylinder check the spring check the cylinder it's a brass color make sure everything is clean inside and put it all back together and careful with the gasket: if it's dirty use carburetor cleaner to clean it. Let it dry just put a light coat of oil on the cylinder. The spring that returns the cylinder could be weak and allowing the cylinder not close::::

  • 1
    How does this account for the issue only happening after riding for 5 kilometers?
    – CharlieRB
    Nov 3 '17 at 12:39
  • It could be Caused-by The engine getting hot: this is why you have to take it apart and see if we have any scrapes on it anything I could stop it from closing freely : You can replace a throttle cable or disconnected f
    – Rev.earl
    Nov 3 '17 at 17:40

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