KDX wont idle when hot

[ons597]

My 97 KDX wont idle when the motor is warmed up. I have to crank the idle screw all the way in to keep it just barely running. If i leave the screw at this setting and start the next day, it screams like it is going to blow, then slows down to almost nothing as it warms up.

Please help because a Bike that wont idle is hard to ride in the tight and technical stuff that I love to ride.

 

[dirtbikingdad]

I'm interested in hearing some words of wisdom on this one. We just bought ours and it's doing the same thing. With ours, the jetting is 145 and 42. It'll start without the choke, so I'm thinking its too fat in the pilot. It seems to like more than 3 turns out with the air screw, which is also a sign of too much pilot.... Of course, I have a 38 but no 40.. :(

If the jet doesn't fix it, I may replace the reeds... I have no idea when they were replaced last. By the looks of this bike the guy just rode it and rode and rode it.

 

[adam728]

My suggestion would be to set the air screw when the bike is warmed up, and if it's out too far, go leaner on the pilot jet. So dirtbikingdad is on the right track.

 

[G. Gearloose]

Clogged Pilot Jet or air leak, I suspect.

 

[guts]

My 97 KDX wont idle when the motor is warmed up. I have to crank the idle screw all the way in to keep it just barely running. If i leave the screw at this setting and start the next day, it screams like it is going to blow, then slows down to almost nothing as it warms up.

Please help because a Bike that wont idle is hard to ride in the tight and technical stuff that I love to ride.

sounds like little rich on the pilot jet . also have you tried moving needle ? anyway i'm no expert but here is a link should help and has more detail . http://justkdx.dirtrider.net/ go to tech tips and you will see carb tuning, alot useful information there .

 

[dirtbikingdad]

Thanks for the info guys and for the original question. I'll post what I find out. :ride:

 

[ons597]

Found the problem, float needle and seat are worn badly, plus float level too high, causes the carb to flood the engine. That is great at start up, probably why i dont ned the choke to start it, but when it warms up, it is flooding itself until I crank in the idle screw and move the slide up, letting in more air to lean it back out.

Check your float needles and float level. If gas drains from the carb overnite if you leave the gas on, you have found the problem most likely!

 

[dirtbikingdad]

Mine's not leaking fuel... I'm really hoping its the pilot and not an airleak.... actually an airleak should make it idle "up" instead of "down" since it leans out the mixture.

I just replaced our needle. Can you replace the seat too? I asked for the needle and seat and he just handed me the needle... The float was set a little high on our... which I thought that what was really wrong with it. Not. I'm hoping the bike shop will have a 40 pilot and I can get to the bottom of what is going on with it this weekend.