So it's a 2009 KLX250sf. I am doing the stage II dyno jet, and I had it together, and when I turned on the gas to fire it up, it started pouring out the carb overflows. I re-accomplished everything, twice, making sure everything was seated, washers and spring were good, and still before even putting it on the bike I hooked it up to the tank, and still it's over flowing. Any help?

Also, the smog stuff to remove is the line from the airbox and engine/crankcase? Basically remove and caps? Any hints on were to buy the caps?

Thanks in advance,

 

Did the needle valve under the float fall out or the flat adjustment get knocked out of whack?

 

I just put in a DJ kit 5 minutes ago. Your float/needle assmebly is cattywampus. You may have lost the hinge pin for the float, upset the needle's seat, or who knows what. The single thing that stops fuel from overfilling the bowl is that little pointy black rubber plug that is pushed up by the white floats to seal the inlet.

Don't worry about the desmog. Capping the hose you describe is a problem, that is the crankcase vent. You only remove and cap the hose that goes from the airbox to the head, if you want, no real benefit.

 

A quick check I always do after having a carburator apart, is to put a short tube on the fuel input. you should be able to blow into the carb when it is rightside up, but not when it is upside down.
Caution: Just a little puff. Too much blowing will get moisture from your breath in the carb.

 

I like that hint -- thanks! a good one it seems.

 

thanks for tips. I'll let everyone know what part I jacked up.

 

Ok, so it's still overflowing out of the float overflow line. I tried the to blow into the gas line, I could do it both rightside up and upside down, so that's bad?

Also, highbeam, little pointy black rubber plug that is pushed up by the white floats to seal the inlet? I see a silver circular piece that the float pushes against?

Ok, so I never heard of vaccum carbs before. I spent my years strickly on two-stroke dirtbikes, where the throttle cable attaches to the sldie. So, I may have let my ego think for myself when I started the carb removal.

Question, is the slide supposed to go all the way down, or is there supposed to be a gap where you can look through through from the airbox side and see the needle valve?

Believe it or not, the bike actually starts, but at the same time it pours gas out the float over flow. I do have to get it throttle if I want it to keep running.

Anymore tips? Thanks.

 

You will be able to see under the black slide. This has nothing to do with your fuel level in the bowl.

This carb is just like every other carb in the universe (well almost) from your lawnmower to those 2 strokes with regards to the float assembly and inlet valve. The white float is hinged. As the fuel level rises, the float floats and pushes a little plug into the fuel inlet to stop flow.

Your little plug is out of place or missing. It needs to be aimed into the fuel inlet hole so that it will work. The plug is a silver cylinder topped with a black pointy cone. Take the float assembly apart to be sure that the black cone is in place and that there is no junk preventing the black cone from passing the walrus test. That is, the walrus likes a nice tight seal.

Another possibility, though unlikely, is that your float is not floating if you poked a hole in it and it filled with fuel.

 

So, still having the issue of the float bowl over flowing. I removed the float and checked the neele for the little black tip, and it was in place.

Does anything in the pics look wrong?

 

Looks like you broke the shroud around the air mix screw. No problem with that though.

Everything looks to be in place from the pics. One more thought, did you loosen or remove the fuel bowl drain screw? I believe it was an allen and threads into the bowl. If that is loose, your fuel will pour out the hose.