Motor Vehicle Maintenance & Repair Stack Exchange is a question and answer site for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

My bike struggles to idle on cold mornings. No issue there: I just open the choke till it warms. However, I must do this ever so slowly and delicately otherwise the engine cuts out. I find this odd as revving the throttle quickly is fine.

Would anyone know why this is occurring?

share|improve this question
Do you mean close the choke and open it as it gets warm? – mikes Jan 3 '13 at 3:56

If you have done any performance mods they may be contributing to your cold idle problem. Exhaust or air intake mods may put you in a borderline lean condition. You could have a lean idle circuit. This could be an adjustment/calibration problem or a dirty carb. When you open the throttle you bypass the idle circuit and the accelerator pump richens the mixture to keep the motor running. If you haven't done any performance mods I would try some carb cleaner. I have had good luck with "SeaFoam" and PB Blaster "lawnmower tune up in a can". Yes that really is the name of the product. I would try the following.

1.shut off the fuel at the tank.

2.start the motor let it run out of fuel.

3.disconnect the fuel line at the tank

4.spray the carb cleaner into the fuel line, completely fill the hose if you can 5.reconnect the fuel line to the tank

6.crank the engine just enough to fill the carbs with the cleaner (approx 5 seconds)

7.let the cleaner sit in the carbs for several hours

8.add some cleaner to the fuel tank and turn the fuel shutoff back on

9 start the engine

It may take a few miles for the dirt and sludge to pass thru the carb.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.