01 kx250 jetting questions

[Shane3004]

 wel lads, just opened me carb, and the slow jet is 42 and the main jet is 162, i have a full pro circuit exhaust system and hopefully getting v force reed valves soon, any suggestions on jetting or are my jets ok?   

[sandblaster]

Here is Pro Circuit's site and recommendations based on 32:1 at sea level
http://www.procircuit.com/jettingspecs4.htm
MAIN 158   
PILOT 52    
NEEDLE POS 2ND   
SCREW 1 3/4
POWER 48
SLIDE 8

[Charlie500]

Be 100% sure your exhaust is clean and your silencer is assembled properly with fresh packing. (I had an extremely hard time jetting my bike because the screen tube was not aligned properly in the spark arrestor.) Be sure your exhaust valve is operating properly. (Easy to do by removing the side cover behind the expansion chamber and watching it while you rev it up.) Make sure your reeds are in good shape and have good gaskets installed to prevent any leaks. Make sure the boot from the carb to the reed block is in good shape with no cracks. Make sure you have some fresh 91 or 92 octane gas and some good premix. Pick a premix and stick with it... (After you jet it your bike may run different with a different kind of premix) Then you can start jetting...Start with what pro circuit recommends. Then you can fine tune it from there. Always keep an eye on your plug... you don't want it white... mocha brown is the perfect color. From my understanding the main jet is for wide open throttle. The pilot and air screw is for idle-1/4 throttle. The needle and the power jet is for everything between.

Correct me if I'm wrong guys...

[motopunk]

first try with the jetting that you have in there,

 if not work, change to a 45 or 48 pilot jet. needle on 3. position and mainjet at 168 or 170 .

thats the jetting, i raced over years in my 97 kx250 without the powerjet and with all kind of pipes. worked well also in nearly all weather-conditions... premix 1:40 with motul 800 and 98octane gas...

if this all not work, try what sandblaster wrote... slowly step by step to perfection  

[Foxx4Beaver]

wel lads, just opened me carb, and the slow jet is 42 and the main jet is 162, i have a full pro circuit exhaust system and hopefully getting v force reed valves soon, any suggestions on jetting or are my jets ok?   

I don't know what your elevation is, but if you're 1000FT or below sea level, I would run what you have.
I'm running nearly the same as you have in my 2000 250...

162 Main
Clip in 2nd from top
N3YE Needle(4 steps leaner over the stock N3WE) 
48 Power Jet
45 Pilot
1 1/2 out on Air Screw
#8 Slide.

The only thing I want to change, is drop my Pilot down to a 42...it's just a touch rich at very slow speeds.
There's a thread on here that member don46 recommended running a #7 Slide to help clean up the very bottom...and I believe it was on an 01, but I'm just not quite "that" anal about it....it runs super crisp and rips just how I have it set up.
Just remember, elevation will play a key role in jetting,and if you're above 1000FT sea level, these settings won't give you the best results. 

[Shane3004]

I live in the south east of ireland, not sure what the elevation is, when i opened it i cud only see 2 jets, the 2 in between the floats, the pilot and main jet, but dident see a power jet, i have a manual and it shows where it is, but its not on mine, and i cant see any hole where its ment to be either? You,s were sayin sumthing about a clip and a slide, are these in the throttle part? My throttle needle and all just screw off the top, no bolt hold it on or anything, but the book says there 2 screws to remove first, im confused, sorry bout all the question, just when it comes to carb set up in lost, anything else is fine ha 

[motopunk]

I live in the south east of ireland, not sure what the elevation is, when i opened it i cud only see 2 jets, the 2 in between the floats, the pilot and main jet, but dident see a power jet, i have a manual and it shows where it is, but its not on mine, and i cant see any hole where its ment to be either? You,s were sayin sumthing about a clip and a slide, are these in the throttle part? My throttle needle and all just screw off the top, no bolt hold it on or anything, but the book says there 2 screws to remove first, im confused, sorry bout all the question, just when it comes to carb set up in lost, anything else is fine ha 

that sounds, that your buke could be older than 2001 , post a pic for comparing and the right year identification  ...

the needle is in the carb-slide, you must take out the bolt in the slide, where the cable was connected and you can take out the needle and you´ll see the clip on its top and the 5 grooves (clip-positions) lowering the needle makes a leaner mid to top. lifting up the needle in the slide makes a richer mid to top-performance... 
but like i said, in first try what you have in the carb... maybe could be, that it works perfektly