Ok, so I bought my '09 a couple weeks ago. I test drove it and everything was fine. Seller said that he was having problems with it at warm temps but that it seemed to be fine that day. He had taken it to a Kawi dealer in the fall and had the carb adjusted. They said it did not need a jet kit, and they simply adjusted the fuel screw and fattened it up. TODAY, I adjusted the suspension, and took it for a ride. After 2 miles, it stalled. I got it started back up, and a mile later, it stalled at a stop sign. I managed to barely get it back home, and started researching and trouble shooting. After having the carb out and apart twice, speaking on the phone with the dealer, AND my carb guy, it appears the bike does indeed need a jet kit. The only mods are an FMF slip on, and a Moose Air Cleaner. I absolutely cannot believe it needs a jet kit with so minimal mods. Spark plug was totally white, and it has all the symptoms of being lean though. NOW.... My cab guy says "Buy a JD jet, the next size up from stock. If it not big enough, we will drill it out." So, I need to know if that Keihn carb has an adjustable needle or not. I did not take notice, and I am not going to tear the bike and carb apart to find out. If the needle is adjustable, all I will need is a single jet and I should be good. Otherwise, I think I will need to buy the $80 kit. I would like to avoid that. I have not looked into Dynojet, because my carb guy uses JD. He has spoken. LOL so to recap, bike runs great until it warms up. Plug is white. It exhibits lean behavior, even though there is minimum done to the bike. Is the stock Keihn needle adjustable with notches for the clip? Thank you for all your help guys. I really appreciate it. I need this thing to run at any temperature. I cannot believe this thing is this sensitive just with a slip on and air filter!

 

09 needs jetted top to bottom. Main, adjustable needle, and pilot. I did Kiehin jetting in mine per the jetting recommendations from D Pippin and others as written in the link for hop ups in my signature. Worked for me, but a stock exhaust. Others use Dyno Jet and KLXter knows them inside and out. He will likely be here shortly, superlatives and all...

 

BTW, I am looking for the JD Jetting kit, and I don't think they even make it for my 2009.

 

KLX678's wish is my command - so I am here !
And, fitpays, fear not, you've "saved" yourself - and your poor bike - by being here..

Let's read between the lines: Your bike runs great - revs to redline and runs perfectly - then the stalling starts and you can barely get it home. There are no issues with the cooling system (getting too hot), the valve adjustment clearances (being too tight), or any other engine issues.
If this is the case then let's go to work:

Your issue has nothing to do with your carb setup (needle, needle settings, jets, fuel screw settings) and everything to do with intermittent fuel starvation. This is: debris in tank(rust?), in-tank screens, the inline fuel filter you didn't know your bike has, needle/seat/float, debris in the bowl, improper bowl venting (venting line non functional), improper routing of the tank venting hoses, etc etc...

The peeps you've been talking to are not necessarily morons, just ignorant or not listening to you when you describe your symptoms - but, they also could be morons..Either way, you should stop talking to them now that you are in the hands of the experts here..

Some points:
Your mods DO NOT require re-jetting or any other re-doing of your CVK if your snorkel is in place - and since you have not described ongoing constant running issues (until the stalling starts), I assume you are running with the airbox lid and snorkel. DO NOT buy any kit right now, and never buy a JD kit, only one of the DJ kits after you've fixed your problem.

White insulators on plug(s) mean good fueling - when burning ethanol'd gasoline. Look this up yourself and then quit attempting to read spark plugs for jetting/fueling purposes and quit talking to morons that think they can..

Your stock needle cannot be adjusted via a clip and needle notches - there are none on the stock setup. In rare cases, I can relay how to make some adjustments on a stock needle (for testing purposes only, while fueling advanced performance mod combos)..

When you've fixed your problem, let us know and we will tell you how to turn your ***** cat into a lion with actual dyno tested, charted, and proven, fueling curves and power curves (no guessing, jet drilling, or "next size up" needed) ! This will be easy for a peep that has torn down his CVK several times without "screwing it up"..

 

The minute someone says a KLX250 in box stock form doesn't need jetted tells you one of two things. They could be held liable for messing with jetting, which is related to pollution standards, should they change it out and the bike doesn't meet emissions testing standards. Or they know nothing about the history of virtually every carbureted KLX250 ever built.

I also agree that there is something other than jetting messing with your bike too.

I will say getting a mile or so between shut down seems to tell me the carb is draining dry, not enough fuel flow. But not being there I have no idea. My bike will go about a mile on open road when I shut off the fuel petcock to run the bowl down. It starts running out and stumbling at about a mile. If you want a quick check for the fuel flow grab the appropriate tool to open the drain - I think it's 3mm allen - on the bottom of your carburetor. Now go out run the bike and when it shuts down Immediately reach down turn off the gas tap, pull in the clutch and shut it off. Then take the tool and open the float bowl drain to see how much gas runs out. If a tiny amount runs out there is likely a blockage - aka junk - plugging up the little filter in the carb and any other place between the tank and the float bowl. There is an in-line filter at the fuel inlet on the carb. If you are fortunate that will be it. Otherwise get a mechanic to troubleshoot the problem.

From there, jetting is your choice. Personally I did Kiehin jets, because they are available at many dealers who actually carry jets and can be had one at a time, no kit. The Dyno Jet and JD kits I don't know about them. The KLX can pick up a decent amount of power when opening up the air box by either installing the KDX220 snorkel, pulling the snorkel and leaving the lid open, or tossing the lid entirely. Depends on your possible uses and how much intake noise you will tolerate. It will require jetting either way and an adjustable needle is definitely beneficial. Of course the other option is to leave it alone, crank over for long periods to get started, and have limited power by restricted breathing and jetting. Your header is a nice shiny decoration in that case.

 

I pm’ed KLXster today. Hoping for some help finding the tank screen and inline filter. I would imagine I could just open the lid on the tank to make sure it isn’t the tank vent. Yesterday was f’ing EXHAUSTING with the carb in and out two or three times. I don’t know if I’ve got it in me today but I’m going to have to sort this out. Ideally before I drop it to get the DJ kit installed. I’d like to get it running right as-is, but I should likely make a decision on what to do with the air box before I get the kit installed.

 

Fitpay and I are "on it" - but guys, when you buy a non-running bike or a bike with carb issues, you are signing yourself up for becoming an "expert" CVK technician. Through hard research, probably a lot of trial and error, and learning from your mistakes, you MIGHT be able to get your bike running right.

If you are lucky enough to find a "CVK Guru" that will do the work for you, and do it correctly the first time, it will be EXPENSIVE !

Once a peep can COMPLETELY disassemble their CVK, identify all internal parts and knows proper settings for them, and can reassemble the carb successfully, I can offer guidance..

Until a peep has reached that competency/proficiency, I can't help much..

 

KLXster knows exactly what he is talking about. I’m going to clean the filters. I’d like to replace them, but it’s Sunday. I’m going to blow them out in reverse with compressed air, then douche them with carb cleaner. I’m really hoping to be able to get to the one on the carb without removing the carb. I’ll also check venting. I’m hoping to be able to get the bike running properly BEFORE doing the air box and jet kit. I’m going to remove the snorkel all together but reinstall the lid. It’s really important to me to get the bike running properly before it goes to the mechanic for the jet kit install. I included screenshots from the manual so anyone following this that is curious where these filters/screens are will see. Sorry the images are so damn big. I really wish I had this info yesterday while my buddy was here giving me a hand with it. I suppose I could let the mechanice deal with all of it, but it is killing me, not knowing WTF is wrong with this bike.

 

OK. So rather than taking filters out of the tank, and risk f'ing something up like breaching an o-ring or something, I tested the fuel flow from the tank, by pulling the hose off the carb. I put a drain pan under the bike, and turned the fuel to ON, and RES. Both flowed fuel faster than a top fuel car could drink it. The internal screen or filter, appeared to be in the hose that I removed from the carb, so that should not be a concern either. I ran the bike up to temp, and sure enough, SAME ****!!!! UGH! I just can't imagine why it would run fine until it warms up, and why it would be a fuel issue, but only when warm. The only other thing I can really think to do prior to it going to the shop is to change the plug. I seriously doubt that is the issue either though. Oh, and I also topped oil off to make sure motor wasn't getting hot from low oil level. Last ly, when it started acting up, I opened the gas cap to rule out a tank vent issue. Still runs ****ty if at all when warm. I might be in over my head with this one, and as I said, the DJ kit is on it's way. The dude working on it for me when I get the kit, has a 450 that he did the carb on, and it runs like it has a hopped up fuel injection setup on it -AT ANY TEMP. I will continue to check back in on this thread so you guys know how I make out and so I might be able to help anyone that is reading this thread in the future, to rule stuff out.

 

I would check the routing of the fuel lines from tank to petcock. They can get kinked, especially if they aren't OEM items. Bike will run for a bit then