screaming kx500

[red]

I have a 2000 kx500 took it out to ride to day started riden and noticed that it wasn't coming back down to idle it seemed like the throttle was 1/8 open even though it was closed. so i pulled in the clutch and came to a stop and the engine started screaming as if i were pinned wide open,the kill switch wouldnt kill it so i let the clutch out and that shut it down.i started it back up ran ok tell i rolled the throtle a little and it started screaming agian,the cable dont seem to be getting stuck and has enough slack.should i replace the cable?

[Rowdy-Yates]

When you roll on the throttle and let go it should snap back really quick. That is how it should work. Some times if you lay down on the throttle side your throttle and bars will bind. I would just check the throttle down to the carb. Sticky Throttle or carb is no good. My friend stopped riding because he had that problem. Must of scared him really good. I would fix that kill switch too that is a $10.00 fix.

[red]

the throttle snaps back,looked at my slide and it returns when i let go with no hesitation.my kill switch works at normal rpm but not when it sreams

[gowen]

sounds like you have a unhealthy lean mixture. Also, check your petcock for clogging. SOunds like something is starving the engine of fuel.

[GDubb]

I had the same problem with mine when I first got it. I was having to feather the clutch just to bring the idle down everytime I came to a stop. I checked the jetting chart here and turns out the pilot jet was lean. Changed the pilot to the recommended size and havent had the problem since. Might want to check into it!

[red]

i noticed my fuel line looked kinked and when i was loading the bike up it burst, fuel  every where. my main jet is 178,pilot58,stock needle in middle clip position.probably clogger fuel line,easy fix.

thanks good info.

[Timbowe]

Phew easy fix.

[Johnniespeed]

My 04 kx500 did a full throttle scream about 4 weeks ago, unfortunately it was raining and I had a bad get off, think I broke a rib. I noticed that the kill switch does not work during this full throttle thing. and that my throttle is not actually sticking. I have ridden it for many hours since and it has not occurred again. I have not checked it yet but I was thinking the float stuck open just once, anyone else had this happen??

[quincyman]

My 04 kx500 did a full throttle scream about 4 weeks ago, unfortunately it was raining and I had a bad get off, think I broke a rib. I noticed that the kill switch does not work during this full throttle thing. and that my throttle is not actually sticking. I have ridden it for many hours since and it has not occurred again. I have not checked it yet but I was thinking the float stuck open just once, anyone else had this happen??

Yes, and it turned out to be the throttle cable. It was not bad but too tight down where it enters the carb. I zip tied it into position so it could pull toward the throttle with a slight bow for slack toward the carb. That fixed the problem. It's also a good idea to loosen your throttle hand control and make sure when you tighten it that you tighten it evenly. It can sometimes bind the cable when not torqued correctly. It's amazing how touchy these throttle cables can be. Don't forget to lube the cable.

[KXcam22]

It is most likely a lean condition that is the culprit, either caused by fuel starvation or a borderline lean pilot jet.  When the mix gets that lean, the engine will run away and the kill button will not stop it since the cylinder mixture must be hot enough to self ignite (like detonation).  You can artificially create this by turning off your gas petcock while the bike is idleing (it's eery and scared the hell out of me - most bikes just stop, not take off).  I also had this happen once when riding, but I was trying a 55 pilot and riding at 0 degress C in 6" snow. Lots of dense cold air making the mix too lean then. With the 58 back in it doesn't happen. Hope this helps. Cam.

[KXcam22]

Nothing like a 500 with a stuck throttle to get your attention!!  I should have added that, as other have pointed out, a stuck throttle cable will also do this, but in that situation the kill button should work (I know that lean it will not).  I have not encountered the KX throttle sticking (yet?) but it certanly can happen to any bike.  As a check, before I ride I always snap the throttle and listen to hear the sound of the carb slide bottoming with a nice solid clear "click".  Repeat with the bars turned full lock. If it does not sound solid, then some repairs or lube may be in order.  In the old days we used to lockwire the cable into the top of the carb adjuster so it couldn't jump out, but old euro bikes were really prone to that. Haven't done the KX. If you don't ride with barkbusters, a small RHS layover can jam the plastic throttle tube against the bar end making it stick, but at least then you can force it closed it by hand. Cam.