Kx 100 Idle issues

So i just bought myself a used 2000 kx100 and theres a few issues with it. The main thing is it wont idle, if you let of the gas it will just die which makes it very hard to kick start. I had my friend tear down the top end and make sure the piston in it was good which it is brand new. Now bear with me because this is my first bike so i dont know much about what im talking about. My friend thinks that the coil is bad because apparently if it is theres not enough spark to keep it going. so that the main issue.

Also if yall could tell me where to get some parts for it too that would be great. It needs new plastics and also a new kick start lever because the one on there is bent to hell. But yea if yall could tell me what you think the problem is with the idle on it that would be great.


another thing he also cleaned the carbie out too.

Check that the Idle screw set correctly.

If it runs and idles with the choke ON and then you turn the choke OFF and it dies,its usually a blocked pilot jet or the pilot jet circuit has a partial blockage in it somewhere,check it again and replace the pilot jet.

Also check that the air screw is set properly and that the seal on the air screw is not worn along with other seals in the carb.

What did your friend clean the carb with?

Edited by ozmx

I'll second this. Look up a diagram of the carb. (It's not as bad as it looks)

Take out the jets clean with carb cleaner, and blow air through them.

Reinstall jets. Reinstall carb.

Kick it over. No Change?

Mess with your idle screw. (Its the black one with the little spring around it). Also it you are super off on your pilot screw setting..this could be an issue.

Also when adjusting. Only adjust when the bike is at operating tempuraters. Not when you first start it. Good luck :)

Don't use carb cleaner unless its motorcycle specific,it destroys rubbers inside the carb.

Been there,done it!use brake cleaner instead.

As suggested above,get hold of a diagram and pull it down for thorough cleaning.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By Rixter
      A tiny clear rubber tube on bottom of carb.  On bottom sort of on side, by floats, the other end just hanging down.  Was it always like this? Or does the other end go somewhere?  Today after multiple trys with kick, choke on/off ,,,fuel keeps pouring out the tube.  This bike has always been hard to start.   Thanx  guys!
    • By Doukis1
      New spark plug, new air filter. Went for a ride and all was good. Hadn't run it in a week and a half. Now it won't start. Getting spark. The plug is dry. Is it possible I over oiled the filter and it has somehow gummed up the carb/ float? Thanks
    • By mbennett95
      My 01' yz125 seems to be requiring a large amount of throttle to get off the line. I've ridden plenty of properly jetted 125's and none required quite so much throttle work from a dead stop. Even slipping the clutch it wont get going without a pretty healthy amount of throttle. Thinking it just needs a clutch rebuild kit and maybe a basket. Any info appreciated!
      If it helps any here is what it has done.
      FMF Fatty, VForce 3 reeds, and an iridium plug.
    • By Sam W.
      Hey all, I just bought a street legal 2005 WR250F. Took it out once three weeks ago. Did about 60 miles on the dirt and 15 on the road, bike ran great. I took it out this past Sunday and was about 75 miles into my ride when the battery died. The battery is cheap, but it is brand new and was on a battery maintainer the whole time while it sat in the garage. I kick started it, and it fired right up. I was on the road for about 5-10 miles in fifth gear when I felt the bike slow down a little bit, and I noticed the sound coming from the bike sounded a bit deeper than usual. About a half mile later the bike started to bog down like it was out of gas. I filled the tank back up and experienced the same problem. The bike began to bog down, then puttered out like it was out of gas. Eventually the battery completely died and I was not even able to kick start it. I trailored it home, hooked it up to the maintainer, waited a couple hours, and the bike fired right up with the electric starter and the choke out. However, it was still puttering a lot when it was idling at this time. If anyone knows whats up, I would appreciate any and all help. Thank you. #Yamaha#wr250f 
    • By Ndh87
      I’ve got an old barn find ‘83 CR80R that needs either a new carb or a rebuild kit. I haven’t been able to find either anywhere. 
      Does anyone know where I can find either?
      housing, bowl and all the hard parts seem fine, if I can find a rebuild kit with a new float I think I’ll be ok. Right now it runs but only when I leave the choke on, smokes heavily and likes to bog down on takeoff