Hi Guys,

Got my 2009 KLX 250S in July '08. Always starts fine. If cold, a pull of the choke is all it takes. The bike always did need 5 min or so warm up. If you went to take off before that the engine would bog down and stall....as most of you here knows happens.

But now, even after the bike is warmed up or hot that is happening. The bike starts fine (cold or hot). Idles fine. But as soon as I go to give it some throttle it stalls often. It did not do this when new, and its really starting to bug me. To avoid stalling I have give it a tiny amount of throttle, back off, give it more, etc untill I get the revs up to 4000+ RPM's and can start engaging the clutch...any lower and the motor dies.

It's really starting to bug me because I don't want this happening in traffic! Twice in the past couple days I approach a stop light, stop, the bike continues to idle fine, then the light goes green and as soon as I give the bike some gas and it stalls!! ...luckily the bike re-started fast those times, but I don't want to get plowed into by the car behind me!

Anyone know why this happens? What the fix is? As I say, when the bike was new it didn't do this.

I started noticing this last year, but I also bought a new Ninja 650R last year and really did ride the KLX that much last year, but I intend on keeping it a long time and need to fix this. It's too bad Kawasaki didn't give the US version of the KLX fuel injection like they did the European version. I would have paid the extra $$ for it. I love it on the Ninja..

Jeff

 

What is your idle speed? And have you ever cleaned out your carb jets?

 

Possibly sounds like your KLX has been sitting for awhile. Your carb may have some fuel buildup trying to form in the pilot circuit or just some crud/dirt buildup over time that becomes more noticeable the more a bike sits. You'll probably have to pull the carb and clean it out with some spray carb cleaner like Chemtool B12 or such. If you do, make sure you pull out the pilot jet in particular and spray the cleaner directly into the bore of the jet and the hole the jet came out of. You may even have to run a small wire through the pilot jet to dislodge fuel buildup. Spray carb cleaner into all jets and passages and blow them out with some compressed air. Have the rubber diapham out while doing this.

 

Also make sure your carb vent hoses are clear. Mine got a bit clogged with mud once, and my bike starting acting similarly to yours.

 

Hmmmm even if my bike has been sitting for days, and as long as I ran the gas out before, it never takes 5 minutes to warm up, I think because of the jetting my bike starts up faster and in less than 30 seconds its warmed up, at least not bogging. My wife's bike on the other hand requires that you ride for a mile with the choke on half way before its warmed up.

 

I remember when I got my 07 and it was stock, it would bog when cold and just started.. After about 5 mins of idling and gradually giving a bit of throttle it would go to normal.

After doing some breathing and jet mods it doesn't do that anymore. I usually start it with the choke out fully for like 10 seconds, then push it in and ride off keeping the R's below about 4500 for 5-10 mins.

 

My KLX use to have a similar issue, but was never really a problem. Keeping the fuel fresh and running a cleaner solution in the fuel when not running helped the issue.

Also, my KLX has a leaky valve seal. So if I don't run the engine for more than 2 weeks, it is a bit hard to even start. But will still start after a good cranking and conitune to run once the engine is cleared up.

 

My 09 was hard starting and the Kawi dealer opened up the fuel/air screw 2.5 turns and solved the problem. The bikes come very lean from the factory and the F/A screw on my bike was less than 2 turns out.
If your carb is stock thats one thing to check.
+1 with CousinLarry....Putting in a DJ KLX300 kit makes a world of difference with cold starting and less need for the choke.

 

Thanks for all the replies guys. Appreciated.

>>What is your idle speed? And have you ever cleaned out your carb jets?<<

I'll have to look again, that LCD tach, while I like it, is not as precise to read as a needle and gauge...1 LCD bar may be 300 RPM...but I'll look again and see if I can estimate a good number...

Never cleaned the carb jets. Is there a YouTube video on how to do that?

Any carb cleaner you guys might recommend putting in the gas tank to try before taking the carb off? (something I am not looking forward to doing...)

Anyone here priced out converting their KLX to fuel injection like the European version of the KLX?

Thanks!
Jeff

 

Carb Cleaner- Any of the automotive carb cleaners will work. They all do the same thing...disolve varnish build-up from gas deposites.

Haven't seen any info on converting to F.I. Would be interesting to hear about though.