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07 starting and idle issues

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Just bought the bike my first 4stroke, set the valve lash and shims everything seemed correct, cleaned the carb bowl and went through all jets and orifices, added new gas, plug. Idle screw and fuel mixture I think I set to stock settings(if anyone knows them for NY please tell me)

So it starts on choke and runs great on choke will even rev great on choke, once bike is warm and take it off choke it runs for a few second and stalls, starts back up OFF choke idles for a few seconds and then stalls again, I have to keep feathering the throttle to keep it running. Pops and back fires through all stages. Any help is appreciated. Thank you

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Forgot to mention the hot start doesn't work I don't even think it's hooked up, if it's frozen will it make the bike run like described? Frustrated I miss my RM 2 stroke

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If il the hot start plunger is stuck open, your def going to see issues from that. You need to def check too see if it's functioning correctly.

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Are you able to ride it at all? My bike has the same symptoms (maybe not quite as harsh as yours) until I take it for a good cruise (maybe a lap or two). After I open it up she idles and runs perfectly, so I've never bothered to tinker around with it. Curious to hear if this is a simple fix.

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If hot start is stuck closed it will run normally, changing my air filter dramatically reduced popping(which is normal on decel) my bike had the exact same symptoms when I bought it I rebuilt the carb new jets and gaskets and that fixed the problem make sure your air/fuel screw is right... I don't think mine was which is a big problem I used team green settings which if I remember is 1 and 1/8 turns out. (Also 07 kx250f)

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Check that you didnt install the carb slide plate upside down.

 

Make sure the hot start is closed

 

Check that the fuel screw o ring is in place 

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had same problem with my 07 when i picked it up. i put new air filter in and wouldnt run, rejetted i have #s somewhere, adjust fuel air screw and runs like a million dollars now. i currently am on a 11 and my bro had the 07 it fires first or 2nd kick now warm or cold while mine has a routine. dont fret once you get adjusted to the 4stroke and its quirks you wont miss the smoker.

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Did you clean the low speed jet good?  It's the small one that is hidden up in a chamber next to the main jet.  You can get it out without pulling the carb if you twist the carb off to the side a bit and remove the large nut on the bottom of the bowl. Then you have to have a screwdriver that will fit up into the chamber next to the main jet to get it out.  It's going to have a very small hole in it but it has to be clean for the bike to run right and it doesn't take much to plug it up.

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I just got to read all the replies today, and i appreciate all the input and help this is the best forum.

So I took the carb back off and educated myself about this while bike and how everything works on it. The hot start was frozen open and broken off (previous owner failed to mention) and just screwed the cover back on. Ordered an aftermarket choke style knob/plunger setup. I'm mechanical I've worked on all types of motors and carbs, just drilled a hole in the brass plunger and pulled it with a screw and cleaned the cylinder with some emery on a tube, and re-cleaned the whole carb and jets, everything should be good to go when the new plunger comes In.

I'll update this thread when it's back together and see how it runs.

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The hot start would have caused your issues, im sure its going to run correctly now  

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Anyone know the right carb bowl setting for the 07, and also the stock setting for the side knob (I'm guessing is the throttle position screw)?

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The bottom of the carb is the fuel screw, which can be anything from 1 to 2.5 turns out depending on altitude, temp and humidity.

 

The side adjustment is the idle screw which is adjusted to get the bike to idle at about 2000 rpm .  

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"The side adjustment is the idle screw which is adjusted to get the bike to idle at about 2000 rpm."

 

How does one know when the idle is around 2000 rpm? Sound? Previous experience?

 

Thanks.

 

Jeff

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My 07 kx250f is mostly stock except the pro circuit full exhuast Ti-4 . And the jets are 182 and 40. With the symptoms I'm having should I run different sizes for Long Island NY

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