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Starting problems

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Hey so i pulled out my 09 kx250f yesterday because it was about 50 degrees. It has been sitting for about 3 months and when i went to start her it would not start up cold i had to pop start it. Then once it got warmed up it would start up one kick, but if i let it sit a while i would have to pop start it again. This also happened the last 2 times i rode at the end of last season but i figured it was from the cold and thought nothing of it. I started thinking it must be the valves but then after i went riding i messed around with it and figured out it would start up cold if you held the throttle about half way. I have no idea why you have to give it throttle when starting it. but when it started using the throttle it would idle fine for about 10 seconds and then the idle would go real low and it would shut off because of to low of an idle.

Any idea why i have to give it half throttle held to get it started?

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It´s a combination of old gas and lean jetting.

Pilot jet and fuel screw settings?

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Not sure, should i try to mess with the fuel screw? Which way would i want to turn it?

I drained the gas before i let it sit and just filled it up with fresh gas the other day.

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The fuel screw is an additional tuning option to the pilot jet. It finetunes the mixture going through that jet.

It´s only effective during starting, idling and up to about 1/8 throttle.

Out (left or CCW) is richer, which is what you want in colder temps.

No more than 3 turns out, or it can fall out.

If it runs best at more than 2,5 turns out, put in a one size bigger pilot jet. Most likely a #42.

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If it sat for 3 months your carb is probably gummed up. A thorough cleaning may solve your problem. Pay close attention to the jets and especially the pilot jet to make sure they are not blocked.

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hey i have a 42 pilot jet from my old 2004 rmz250, will that fit in the 2009 kx250f carb?

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hey i have a 42 pilot jet from my old 2004 rmz250, will that fit in the 2009 kx250f carb?

Yes it will.

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If the carb work doesn't solve your problem, might want to check your valves. my 07 will not kick start cold but can be bump started. once it is warmed up it will kick start.

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yea that's what i was thinking until i found out that it will start right up if you hold the throttle open while kicking it.

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Hey whats the easiest way to pull the carb out, it looks like a Pain in the ass with the aluminum frame? Do i have to disconnect the throttle cables?

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Hey whats the easiest way to pull the carb out,

Remove the seat, silencer, shock, and subframe. It doesn't take but about 5 minutes to remove all this and it's much easier to get to the carb with it out of the way.

When you go to put it all back together put the carb on and then attach the air boot to the carb but don't bolt the subframe back until you put the shock back in. This way you can be 100% positive the air boot is connected to the carb properly. Just push the subframe to the left side to get the shock back in and then bolt the subframe back down.

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So i pulled the carb apart and cleaned it out, there was a 45 pilot and a 182 main in there so i put a 42 pilot in and left the main, then i turned the fuel screw out 2.5 turns. Tried to start it but still wouldn't start so i am guessing valves. When i was putting the throttle cables back into the carb i couldn't really figure it out if you tighten them down the throttle sticks so i had to leave them really lose. Is this ok?

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When i was putting the throttle cables back into the carb i couldn't really figure it out if you tighten them down the throttle sticks so i had to leave them really lose. Is this ok?

No.

Something is wrong if you can´t tighten the locknut on the cable. Make sure that there is slack left by slacking the inline adjuster when tightening the locknut.

Inspect the routing. Also check for fraying of the wire, and make sure the triple clamps does not pinch the cable.

It´s very dangerous to ride with compromised throttle cables.

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Well if i tighten the nut the whole cable spins first off so its hard to get it tight because once you take pressure off the cable just spins right back to its original position. Then if you do get it snug against the carb the throttle will be so hard to turn and just stick.

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Well if i tighten the nut the whole cable spins first off so its hard to get it tight because once you take pressure off the cable just spins right back to its original position. Then if you do get it snug against the carb the throttle will be so hard to turn and just stick.

There should be 2 lock nuts on the cable. The cable should not twist.

Did you loose any of the locknuts?

I could not find a good picture, but here is how it looks:

Dsc_0010.jpg

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No theres a lock nut on the actual cable? I thought it was just that metal piece on the end of the cable and the little nut in the carb, so i clipped the little nut into that groove and then twisted the metal piece on the throttle cable witch moved the whole cable.

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No theres a lock nut on the actual cable? I thought it was just that metal piece on the end of the cable and the little nut in the carb, so i clipped the little nut into that groove and then twisted the metal piece on the throttle cable witch moved the whole cable.

It was a while ago now since I messed with the cables, but I remember clearly that the cable should not twist, there is a locking system that works quite well.

Take another close look, maybe have a look at another bike to be sure?

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I was able to get the cable snug up against the carb but then it was insanely hard to twist the throttle and the throttle would not even think about springing back.

I had this same problem with my old 2004 rmz250 and i somehow ended up getting lucky. The only was to have the throttle work right is if it is lose and not snugged up. I must be doing something wrong.

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