KX Riders

Maintenance & Technical => KX500 Original => Topic started by: dans89kx500 on September 17, 2007, 11:40:21 AM

Title: Idling Problems KX500 1988
Post by: dans89kx500 on September 17, 2007, 11:40:21 AM

Hello,

I have a 88 kx500. My problem is, when I start my bike (with the choke on),  I push down on the choke to turn it off, the bike idles very high (like wide open). Then when I pull the choke back up, it idles fine.... What is going on here??

Thank You,

Daniel in Vacaville, CA

Title: Re: Idling Problems KX500 1988
Post by: Hillclimb#42 on September 17, 2007, 12:17:58 PM

 It is leaning out for some reason. Base Gasket possibly. Clogged pilot jet. Clogged fuel line some where, petcock or in carb. Similar thread in "Bike tries to grenade itself" and thats what will happen, if you don't find the air leak. Good Luck

Title: Re: Idling Problems KX500 1988
Post by: maddoggy on September 17, 2007, 02:25:06 PM

i agree with hillclimb's suggestions, you need to find the leak. another idea would be to check the carb to intake boot for cracks. if your bike sits out in the weather extremes the rubber boot takes a beating and starts to weather crack. a crack could be all the way through.   MADDOGGY

Title: Re: Idling Problems KX500 1988
Post by: alan on September 18, 2007, 02:47:19 AM

I would agree on the clogged Pilot jet, I have had that happen lots of times!

Alan :-D

Title: Re: Idling Problems KX500 1988
Post by: don46 on September 18, 2007, 02:53:04 AM

Once the bike warms up, and you turn the choke off does it idle fine? While this may sound off, it's true, you may be rich on the bottom end, and to make it idle you have turned in your idle screw forcing the slide up. The slide is now in a position that allows the bike to idle right for normal conditions but because it is touch lean for the slide position when cold.

Now mind you I'm assuming that when its warmed it idles fine, if so then look at my synopsis, if it idles high all the time with the choke off, you have an air leak or carb issue.

Title: Re: Idling Problems KX500 1988
Post by: dans89kx500 on September 18, 2007, 02:03:39 PM

Thanks for the suggestions. Yesterday, I took the carb off and shot some carb cleaner through some of the jets (I'm not a experienced mechanic). I did replace the jet, that is connected to the float. I started it up today. It did Idle a bit better, but I still had that out of control, wide open, bomb about to go off idle. When it idles crazy like that, I pull the choke and it idles fine.
I believe it could be the intake boot. It is cracked and my bike does sit covered outside.


Thanks for the suggestions, I will look into all of them. If you have anymore ideas please throw them at me.

Daniel in Vacaville CA

Title: Re: Idling Problems KX500 1988
Post by: BA500 on September 19, 2007, 03:50:13 PM

Just a guess, but is there a screen inside the fuel petcock which may be clogged?   :|

Title: Re: Idling Problems KX500 1988
Post by: KXcam22 on September 19, 2007, 05:32:04 PM

An easy check is to run an unlit propane torch over the cracked areas.  An air leak will suck in the propane, richen the mixture and change the idle. Cam.

Title: Re: Idling Problems KX500 1988
Post by: Hillclimb#42 on September 20, 2007, 02:44:36 PM

 When you pull those jets, you need to look thru them at a light to see that they are clear. Check throttle operation before remounting carb. The slide should slam closed and have just a fuzz of play in the throttle tube. 88 probably has worn slide also. On the other thread, there are some other possibilties to look at.