So little back story, got a 2009 klx250s with less than 15mi on it and Im pretty sure had the same gas since day 1. Drained tank and pulled Carb for cleaning. Never dealt with carbs before and had no idea you were supposed to count turns on the jets to get them installed correctly. So two questions, can anyone tell me the number of turns they have experienced on stock jets? And can anyone give me a carbs for extreme dummies and possibly tell me what all the things do on the Carb? Pic attached thanks!

 

There are 'no' turns on the jets, only the air screw that you adj from outside the carb after the bike is running.
My suggestion is to remove all jets, the float & bladder (don't boil these), and boil in water on the stove for an hour or so. Then lube and put back together like you found it. Adj the float before you put the bowel on.
But I am not an expert, they will be here shortly.
Did you go to the manuf web site?

 

Have you even tried to start the bike?
Remove the two jets between the floats. The one in the picture closest to the right float is the pilot jet and works in the idle mixture circuit. The hole in it is very small and can easily become restricted. Inspect that jet and the main jet to the left of it. Return them to just a snug tightness. The adjustment at the top of the photo is the pilot screw and works in parallel with the pilot jet. That one is adjustable. Start with it at 2 1/2 turns out from seated.

That should get you started.

Ride on
Brewster

 

Thanks for the replies! Yes I have tried to start it after I tore the Carb apart and all it did was crank continuously no matter the choke position. After some finagling we managed to get it running but it was extremely rough idle and would die after a few seconds, the one time I did managed to get it started and stay running it would not run without the choke even after letting it warm up.

 

I hade a CBR years ago that wouldn't run without the choke on (couldn't turn the choke off until I was on the highway). The previous owner let it sit for a few years without draining the fuel. I finally had to take it in to the dealership & they soaked the carb overnight & scrub the orifices. They ran copper wire through everything to clean it. It ran like a champ after that very thorough cleaning.

 

Yea I didn't have a flat head long enough to take out the pilot jet or any wire to run through it, will be making a trip to that parts store today to get something to pull that pilot jet out. How much does the air screw mess with the carb? I had it running for about 5min this morning but when I turned the screw nothing seemed to happen.

 

The symptom you describe sounds like a classic pilot jet problem. Clean or replace that jet and clean the main jet. How bad does the carb look and smell? It doesn't look too bad in the pic, but a pilot jet plugs easily when fuel left in the carb dries.

The mix screw on this carb is actually a fuel screw, not an air screw. When seated, it has the tightest limit on the amount of fuel through the pilot jet circuit. Opening it lets more fuel through the pilot circuit. You should find highest idle (best setting) somewhere between 1 and 3 turns out and Brewster's recommendation is a good point to start. When you pull the jets, look at the numbers and let us know what they are. If the pilot jet is too large, the mix screw setting has little to no impact on idle speed.

See the FAQ link in my sig line and find "Care and Feeding of the CVK Carb."

 

While you are at the parts store get a gallon can of carb cleaner. It looks like a paint can and has a basket inside to hold all the parts. Disassemble the carb--at least remove the float assembly and the jets, but not the top end vacuum assembly-- and soak it for 20 minutes or more in the carb cleaner. Wash everything with water and thoroughly dry everything...preferably with compressed air from a compressor. Blow the compressed air through every orifice/passage in the carb that you can find, but BE CAREFUL not to blow carb cleaner right into your face or onto the hood of your new car. Reassemble, adjust the float, replace the bowl screws with hex head machine screws!, and pop the bowl back on.

 

It would be even better if the carb cleaner can could be set on something to vibrate it. From a long time experience in a dealership I can tell you if a passage is plugged up it can be a nightmare to clean out unless you have access to a carb washer or an ultrasonic cleaner. They vibrate and gyrate working the cleaner up into the passages and break up the gunk that can turn into a gummy mass.

While the carb is apart odds are it has never been jetted. You can either do the KLX300 carb parts mod or do a DynoJet kit. I have a link in my signature that tells about the KLX300 parts to order and some mods to make the bike start and run better. KLXter has the stuff on the DynoJet kits. Either one will make you much happier when starting and riding the bike.

 

Just wanted to chime in, this thread is great, good info, and a great help for someone who is trying, but has little previous experience. Thanks!