01 KX 250 Idle adjustment?

[KC10Chief]

I just bought an 01 KX 250. I'm pretty new to the dirtbike thing. Anyways, I've done searches on here but can't find a definate answer. The bike fires right up especially with the choke on. Once I take the choke off though, the RPM's drop and it will die in about 10 seconds if I don't rev it real quick. Is this normal for a two stroke? If not, how do I adjust it? I've read that you can turn the choke knob, or that there is a screw on the carb. If anybody knows, please let me know before I screw something up! Also, I haven't rode the bike yet other than for a couple minutes. Will it stay running once it warms up? I'm taking it out for a ride at the local trails tomorrow. Thanks for any info! Matt

 

[CaptainObvious]

Two-stroke engines require fine adjustments for varying atmospheric conditions (temperature, humidity & altitude). There are two adjustments on the left side of the carburetor.

The first is the air screw. This is the recessed screw head found towards the back of the carburetor, where the carburetor and the airbox boot come together. Turing the screw in reduces the airflow through the carb circuits, making the mixture richer. Turning it out has the opposite affect. This screw is adjusted for maximum throttle response.

The second screw, and the one I think you are more interested in right now, is the idle adjustment. Towards the center of the carburetor, you will see a screw that has a small spring between the screw head and the carburetor. Turning this screw increases the idle...and out lowers the idle. Make sure to "blip" the throttle each time you adjust the screw.

 

[DWreck]

I agree with all above. A lot of people don't like to run an idle on two stroke mx bikes because it takes away some of the snap or responsiveness of the motor. Also note that these are high performance motors and you don't want to let it sit and idle or it will load up and foul plugs. If it is jetted properly you should have some leeway but to be safe while you are getting used to the bike and its power delivery pull in the clutch and clean it out (rev it up) every once in a while. Congrats on the new bike. If you have even half the fun and good luck with it that I have had with mine it will be worth every penny. I look forward to meeting one of these days. Have fun and be safe!

 

[Gringo]

Agree'd

You should be able to set it up so it idles for 10-15 seconds before dieing..Who needs idle on a 2banger?

Gringo

 

[CaptainObvious]

Agree'd

You should be able to set it up so it idles for 10-15 seconds before dieing..Who needs idle on a 2banger?

Gringo

If the carburetor is jetted and set up properly, it should idle all day (an over simplification) and never stall.

 

[Gringo]

If the carburetor is jetted and set up properly, it should idle all day (an over simplification) and never stall.

This is true,however, As its was pointed out before Two strokes dont enjoy idleing for to long and it reduces the responsive snap of the motor ,even if it is only very slight.

Why would you need to idle for more than a few seconds anyhow? :think: The point is if it doesnt hold idle its not going to effect it or stuff anything.

Matt, I suggest you leave it as is, Its set up fine. The motor is not up to temp when you start it so its not running efficiantly and will want to stall, Just like any motor! If it runs fine when its worm then bobs you uncle.

Gringo

Gringo

 

[darringer]

If you trail ride with the bike, or even hillclimb, it's nice to have the bike idle. Especially when negotiating long, nasty downhills and tight trails. My bike has plenty of "snap" off the bottom and will idle all day without loading up. If jetted and adjusted correctly it will idle just fine.

 

[Gringo]

Point taken

I guess its just been to long since i rode anything but moto tracks and have a one track mind..Either way i dont see it as a problem just a preference,long as you bike runs well

Gringo