I have a 2005 kx 125 bored and stroked to a 150, i am having prob getting it to idle the screw is in as far as it can go i am new to carb tunning i have 370 main 45 pilot and the clip is in #2 spot i was having prob with low end bog it had a 27.5 pilot and the clip was in #5 pos

Valve timing not set correctly.
If you increased the bore the carb needs to be re-jetted.

first drain your float bowl. you may have water in the fuel. if this doesn't help then you must clean out the carb. you will need a can of spray carb cleaner. remove carb float bowl. use the right size screwdriver otherwise you will strip the screw heads. remove 2 jets and clean, clean the bores for the jets. use a strand of copper speaker wire to probe the holes in the jets. now you have to clean the idle mixture adjustment bore. first turn the screw closed counting the number of turns to gently seat the screw( write it down). then back out screw all the way- do not lose the spring or washer. spray carb cleaner in the hole . lastly spray the float valve backwards from normal flow. put it all back together. adjust idle mixture screw, start engine and allow to get hot then adjust idle speed screw. if you notice a flat spot back out the idle mixture screw a little bit until the hesitation goes away.

if your talking about fuel mix oil the best is either amsoil or red line fully synthetic oil is the best out there(not cheep though)...if your talking about engine oil (wet clutch)i think bel-ray is the best..(thats what i have had best luck and less breakdowns with)

fuel filter or carb?

The idle circuit is still plugged up or it would not be giving you this problem. Remove the carb and dis-assemble it then soak the parts in denatured alcohol for 30 minutes. Then use a spray carb cleaner to finish the job. Spray into all the little holes in the carb body. Especially spray into the air screw and throttle screw holes. Reassemble the carb and LIGHTLY seat the air and throttle screws then turn each of them one and one half turns outward. This is the factory setting. Before putting the slide back into the top of the carb, move the clip on the jet needle one notch lower on the needle. This will richen the low end fuel mix. Install a new spark plug and clean the air filter. Please rate my answer. Thanks.

see how far your idle screw is turned in if not your slide barrel in your carb is sticking back srew counter clockwise an see what happens

hi,,your carb wont do...its not big enuf airflow..but .the main jet for a vxr200 is a 1.18 or 1.20 (the 125 main jet is a 1.07).
i am haveing the same probs with a vrx 200 i bought..they run fine up 65mph & then seem to run out of fule...but chime back in when drops below 65mph..i have put the bigger main jet in & it doesnt make no diffrance..the carb carnt get enuf air to go above 65mph..carb of a 180-200 will sort it out but it may still need rejeting to suit big bore kit!!....also there is the carb of the dna 180 scooter as well.....good look..Howard

on the carb you will find 2 screw one will be quite far in than the over thats the one you adjust this is the mixture screw which controlles the air and petrol together unscrew it say 1/4 a turns at a time and see if it improves if it gets worse screw it the oposite way and see if that improves good luck buddy

get the bike started, hold the engine at a high idle. while holding the idle high, adjust the air fuel mixture screw until it sounds smooth. rev it up a few times and see if the engine is "snappier". let it return to an idle, then adjust the idle screw. it may take a few tries to get it right, just listen to the engine.. if this dont work, you may consider re-jetting the carb. hope this helps...

Pull the carb off the bike and clean it inside and out. Be sure main jet is clear. Remove the two screws on the outside throat of the carb and spray into the screw holes as well. Be sure to put these two screws back in the same hole they came out of. IMPORTANT > > > do not tighten these two screws down. Only screw these in until they LIGHTLY seat. Now turn each screw one and one half turns outward.

Put the rest of the carb back together and install the carb. Turn the gas on to let the float bowl fill then start the engine. Chances are this will fix the problem. I suggest that you install an in-line fuel filter to prevent this happening again.

Last item> You should have just a little bit of slack in the throttle cable where it goes into the top of the carb. Not more than 1/16". Let me know how things turn out.

Please rate this solution as " FixYa " if all goes well. Thanks