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2014 kx250f Weird idle questions?

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Hi guys, i recently bought a 2014 kx250f off a good friend with 18 hours on it.

Since then i put only 3 hours on it.

On my second ride with the bike i noticed the bike getting pretty hot and starting to idle weird.

I don't know if i am just being paranoid but when i rev the bike with the clutch in or out, in neutral or in gear, it has a kind of drone to it.

The easiest way to explain it is, for example lets say the bike idles at 1500rpm normally, when i rev the bike to whatever rpm and let go of the throttle, the rpms will go back to about 3000rpm for atleast 5 seconds before it goes back to normal idle, other times even longer.

I don't know if i am freaking out, but it is extremely annoying when riding.

Any help would be GREATLY appreciated!

-Ivan

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Just out of left field but is the hot start sticking open?

I don't even know if this bike has one but a buddies bike was doing a very similar thing and the hot start had stuck open

Edited by Goobersbro

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Nope it's fuel injected so no hot start.

And it can't be the idle adjustment screw because the bike has a proper idle normally.

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sounds like maybe need to lube the cable and make sure there is no dirt under the throttle tube. I just did this to my 12' Its like new now

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Hi guys, i recently bought a 2014 kx250f off a good friend with 18 hours on it.

Since then i put only 3 hours on it.

On my second ride with the bike i noticed the bike getting pretty hot and starting to idle weird.

I don't know if i am just being paranoid but when i rev the bike with the clutch in or out, in neutral or in gear, it has a kind of drone to it.

The easiest way to explain it is, for example lets say the bike idles at 1500rpm normally, when i rev the bike to whatever rpm and let go of the throttle, the rpms will go back to about 3000rpm for atleast 5 seconds before it goes back to normal idle, other times even longer.

I don't know if i am freaking out, but it is extremely annoying when riding.

Any help would be GREATLY appreciated!

-Ivan

your TPS could be off slightly.

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This only happens when it gets hot.

Therefore, the throttle cable or the idle knob is not the problem since it idles fine when its cold or warm.

Only when it gets hot it starts to do this, like 45 minutes into riding with about two 3 minute stops.

Also, when it starts idling weird, it gets extremely peppy.

By turning the throttle by a millimeter already makes it go.

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clarify what you mean by HOT, is the radiators loosing coolent out the overflow ?

 

You might be running the bike way too hot by idling for 3 minutes at a time which you should not be doing on a 4 stroke with no cooling fan.   

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Ive never idled it for more than three minutes.

Heres the kicker, the previous owner made the overflow tube go back to the radiators like a circulatory system or w/e he called it.

Could that have anything to do with it?

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Ive never idled it for more than three minutes.

Heres the kicker, the previous owner made the overflow tube go back to the radiators like a circulatory system or w/e he called it.

Could that have anything to do with it?

You cant circulate the pipe back to the radiator, if it gets very hot it needs to release the pressure.

 

You can have the hose go into a overflow bottle which when the engine cools it will suck the coolent back into the rads, even the coolent bottle needs a overflow to release any pressure.

 

If you unsure post a pic of your setup and i can tell you if it can work or not.     

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I've had my bike sense it was new and it does that and I'm starting to think it's normal. I'll ride it good and hard and when i stop it'll idle high for about 5-10 sec and go back to normal. I saw a video on youtube of a guy racing a brand new 2013 which is the same bike and it did the same thing. When he finishes the race and stops for a second is when it does it. Its 11:54 in.    

 

The question I have is why my bike sometimes takes about 10 kicks when it takes normally 1-3 kicks any other time. It only does it when it's hot. It runs fine after this happens to. Do any of your 14s do that. 

Edited by Thunder Bike

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My 2014 only starts when I crack the throttle about an 1/8 try giving it alittle gas maybe. Mine from the start always started no matter what on the 3rd kick with a small amount of gas right as I kick it over

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My 2014 only starts when I crack the throttle about an 1/8 try giving it alittle gas maybe. Mine from the start always started no matter what on the 3rd kick with a small amount of gas right as I kick it over

 

Absolutely the same situation! When bike was new it didn't needed any throttle to start from 1-3 kick. Suddenly it didn't started after 50 kicks... if I add 1/8 or even 1/10 throttle it starts from 1-3 kick as before.... what can it be?

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I was at the track yesterday racing and my idle was horrible. It was low and weak. I was going around the pits in first gear wacking on the throttle and it would bog and respond so late so I grabed the tps with my hand and forceably moved it the same way in your diagram as number b and the idle becuase stronger and instantly responsive when I move it enough. But it has that hex screw in it so it didn't move more than .00001 of an inch so try that by hand first to see if it helps if not losen the hex screw alittle and move like number b

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