Hey everyone, I'm new, I've had a 2009 klx250sf for about a month now. I started upgrading it and so far I put on a fmf powercore 4 slip-on and a twin-air air filter.
Today my Dyno Jet jet kit arrived. I went with the stage 2 so I installed the needle with clip on 3rd spot, 128 jet, and removed the fuel mixture plug and adjusted it to 3 turns.
I basically followed the instructions.
I went to start it and it would only start when choked. It idled fine when choked but would die when unchoked and it would continue to run if I twisted the throttle and kept the rpms up. I checked to make sure all the hoses were hooked up and now I'm stumped. Any ideas?

 

Those sound like the classic symptoms of a clogged pilot jet circuit, but the installation of the DJ kit shouldn't have contributed to anything like that. When you did the air/fuel screw under the carb, are you sure you didn't screw in the air/fuel screw back into the body a little too strongly before backing out the 3 turns?...sharp tip bent or broken. Did you get the air/fuel screw's o-ring and spring oriented correctly? How long did this bike sit before installing the DJ kit? On the 3 turns on the air/fuel screw, you might want to turn it back to about 2.5...3 turns can allow it to back out after awhile.

 

You might also pull the top of the carb off again and look at the slide diaphram and see if it is seated correctly, if not it could be pulling some air there and might also cause this. It is hard to get it back just like it came out as it grows some when the air hits it and makes getting it just right difficult.

 

Your Stage 2 is correct for your setup, and it will run correctly if it was done correctly and if everything was put back together correctly, as long as you didn't get dirt into it. So, retrace your steps, including seating the undamaged diaphragm correctly with all the o-rings and gaskets on correctly.

But, perhaps before you go back into your carb, make double-sure your carb lines are routed right, with no kinking. It will be something simple that's causing your problem....

 

It looks like my fuel mixture screw was in way too tight but when I unscrewed it the screw head rounded off
I'm a newbie at this stuff. I thought an engine compartment on a 95 camaro z28 was tight but the spot where the carb is on this bike is unreal....
Thanks for the help so far guys

 

??? how do you round off a flat head screw that should already have been a couple of turns out ?

Are you sure you are "adjusting" the right stuff ?

And i still believe pulling the carb on the KLX isn't really that bad. Alot easier than pulling the carb bank on my 6R.

 

It just kind of chipped when I went to turn it. I'm positive I'm adjusting the right thing.

 

Yeah, that's why I mentioned it in response to the original question. I've seen the points of these air/fuel screws broken off in the passageway or bent to such a degree that they were unuseable. The good news is that since the needle is made of brass, you can usually get it out with some simple methods. Sounds like a good time for Kouba screw.

 

The screw wasn't too much of a hassle to get out. Bad news is it's gonna take a few days for the local motorcycle dealer to get one. Guess I'll be riding my honda cm250 to school next week

 

Can't you put a new slot in it with a hack saw or dremel tool?

David