Its Back!!!! Man this is ticking me off. The KLX250S ('09) was running pretty good. Well, two weeks ago I put it on my trailer behind my RV and drove my RV over to a place to have some work done on it....then rode the KLX home. Seemed ok. Monday I rode the KLX back over to get the RV...seemed ok, but I did notice a little "bogginess" when starting off in 1st gear, but once going the bike flew down the back roads I took pretty good. I get to the garage where the RV is and I park the bike to pay the guy and talk to him a bit. I then start the bike to load it on the trailer and notice it sounds like its having trouble sucking gas, even the mechanic said "Do you have the gas off?". Well, I was able to rev the engine enough to keep it running as I loaded it on the trailer but it sounded like it wanted to stall. Got the bike home. Unloaded it from the trailer. It sat for 15 min then I wanted to use it to run out to my parents. It start and idles fine. I then give it a little gas and it dies! Does this a couple times but I get the bike going and ride it to the end of my block...but now any attempt to give it gas and it stalls!! This is REALLY ticking me off!! The bike is only two years old!

Anyway, I decide I better not take the bike to my parents. I HAVE to get there, my dad needs to go see his heart doctor and I don't have time to screw around on a bike that stalls on a whim. I start PUSHING the bike back to my house. After about 5 tries, with the bike rolling, I am able to get the RPMs and keep the bike running until I can get slip the clutch out and get the motor getting some power to the rear wheel...and am able to ride the bike back to my garage........but now WTF!!! I am sick of dealing with this nonsense.

I REALLY didn't want to become an "expert" on carbs, especially just because the one on my Kawasaki works like crap! But I guess I am going to have to. 32 years ago I learned how a computer works by building one from a kit (IMSAI 8080)...I suppose I can learn in detail what all the parts on a carb do. It's just we are going away in the RV in two weeks and I wanted to bring the KLX....if I get this all apart and can't get it back together in time it will suck....

I wish I could find a used Keihin CVK34 I could take apart and play with and learn from. Anyone got one? hehe I did find these pages:
http://www.gadgetjq.com/keihin_carb.htm
http://www.youtube.com/watch?v=YnzzUOcXqLY&feature=fvsr

But anyone know where I can find drawings, pictures and info on the Keihin CVK34? I want to know EVERYTHING about how it works. And why it currently keeps stalling my bike!

Thanks,
Jeff

 

Jeff, they aren't that complicated. Just get a decent diagram of it, bite the bullet, and take it out and manually clean it. You'll wonder why you didn't do it sooner. Oh, I would be VERY careful if you follow the advice to stick a wire in the jet to clean it out. I wouldn't do that...I WOULD use a stiff nylon bristle...it won't gouge out the edge of the hole, which can cause problems.

MAKE CERTAIN your vent line off the carb is clear----pull it off and trace it all the way down the lumen to the ground. If you have a dirt dauber nest in it, or a chunk of mud, or a kink, it will play havoc with the engine.

There are plenty of people willing to help you if you get stuck...

 

I wonder if you reached down and pulled the choke maybe holfway out if the bike would have reved for you? That would rule out the vent lines.

You probably have a bunch of crap floating around in the fuel bowl that gets sucked up into the jets and plugs them.

You'll be doing a "gumout rebuild" where all you're doing is cleaning the bowl, jets, and float valve before putting it back together. You shouldn't even need to shove anything into the jets but if you do, something softer than the brass is a wise choice.

 

You might also want to pull your slide and clean it off, if it's sticking at all, it could make it bog trying to throttle up if it doesn't respond well.

+1 on cleaning the openings and carb cleaner throughout. I really like to fill the tubes with cleaner, let it sit a couple minutes and blow it out with my air compressor and a focused tip.

You can check the slide movement by just lifting it with your finger in the throttle body when it's off the bike, if it doesn't move smoothly and there's any kind of hang-up, pull it and clean the slots and the slide. There is some resistance to moving it fact because the air has to transfer from top to bottom but it shouldn't feel sticky at all.

 

i had a simmilar problem with my klx after it sat for a month. the only way it would rev past 3 grand was with the choke on, and it was still a dog. i went for the good ole go or blow technique, and went as fast as i could with the choke on, reached down and pushed it in, there was a cough and sputter, but it's ran great since. what it boils down to is gunk built up in the carb.

 

These carbs are very temperamental, especially to old gas

Don't you still have a year factory warranty?

If not, just take it in to the dealer. My bike is an 07 250 but I bought it new just six months ago because it was a "safety riders course" bike so Kawi sold it as new with 150 miles on it and a full warranty for pretty cheap. Anyways, when I got it, it had been sitting for about the last 8 months. I drove it home from the dealership and it also had problems with the carb, but mine would not go back to idle. When I pulled in the clutch, the motor would stay revved for about 5 seconds and then go to idle. Took it back to the dealer the next day, they got it right in, and about 20 mins. later, bike was as good as new. They said one of the jets was clogged.

Even if you had to pay a few bucks, a quick trip to the dealer would probably be the easiest.

 

Thanks for the replies guys, think I may have some time tomorrow to take it off the engine and try and see what's going on. Will report back what I find...

 

To prevent this from happening NEXT time: I just bought an 09 that was purchased in July of 07. It had 45 miles on it! That's right...the first tank of gas was still in it. Although I ran it 267 miles (filled it a couple of times in there, and added cleaner to the fuel) prior to taking off the Carb to re-jet it, it was SPOTLESS inside! I emailed the Previous Owner, he said he used Red Stabil in that tankful, and uses it in all his engines, and has never had any trouble.

I'm sold on the stuff for storage of engines, simply based upon how clean this carb was.

 

+1 on the Stabil I had an old 1985 klr that I had to totally clean the carb on two different occasions. Both times after leaving fuel set in it too long. After the second time I learned my lesson and started putting stabil in if it was going to sit very long. After that no problems.

 

My klx 250sf is doing the same crap. It has 1100 miles on it, yesterday was running fine, pulled off exit ramp, then stalled. Would idle, but die as soon as i gave it gas. Pushed it home 4 miles.

Pulled plug, looked fine. Drained carb out, then started right up and ran fine. Thought I had water in tank somehow, and that I had solved the problem.

Drove to work 20 miles, no problems. Left tonight, started, ran fine, then bam, same thing. Bike died at traffic light, and would start but only idle, and die with any gas. Tried same stuff at gas station...drained carb, but no help this time. Then I wiggled a bunch of the wire, no help, then bike started again and ran fine without knowing what I did to achieve this.

Can't find any kinked ignition wires, hoses. This is frustrating b/c this is a brand new bike that has run fine up until now.

I drive this bike daily, and it is only 5 months old, so I doubt it is the carbs.

Any ideas?