kx 250 problems

[Adam Lyzwa]

i got a 05 kx 250 f i got it yesterday and it would bog past half throttle i messed with the mixture screw and it ran better but was still not running the best. I decided to clean the carb today and after i got everything out back together i tried starting it i tweaked with the mixture screw more and it finally started it only a starts with hot start and choke and it runs ok then when i turn the choke off and give it throttle and try and make it die it backs fires pops a couple times and just dies does anyone have a idea of what it could be ? 

[William1]

Did you take the slide out? Put the release plate back in with the flat side down (hole on the bottom?) Did you try and clean the carb with strong solvent? Did you ensure all orings were put back in? Did you ensure all passage ways are clear?

Fuel screw is a fine adjustment on the pilot circuit. Typical setting is 1.75 turns from gently closed.

[Adam Lyzwa]

Alright well the day after i posted it i went to start it and it started like nothing and ran way better so the carb clean did help it’s been a week or two since that and now it stoped starting it starts and even if you hold the gas it dies then it won’t start at all only starts once it has spark i tipped it over and has was leaking so the float height is good i have no glue what it is it has spark too it does have love compression and i have all my parts ready but i want it to start now before i put in new rings 

[Adam Lyzwa]

1 minute ago, Adam Lyzwa said:

Alright well the day after i posted it i went to start it and it started like nothing and ran way better so the carb clean did help it’s been a week or two since that and now it stoped starting it starts and even if you hold the gas it dies then it won’t start at all only starts once it has spark i tipped it over and has was leaking so the float height is good i have no glue what it is it has spark too it does have love compression and i have all my parts ready but i want it to start now before i put in new rings 

i checked if the slide is the right way it is and i tried messing with the mixture screw but that doesn’t help i’m so stumped 

[kxrob]

go back to standard and start from there

treat it to a new pilot jet but would go to a 48 not a 50

set air screw at 1.75 out as suggested above and put needle clip in the middle

make sure the choke circuit is clean in carb

double check your fuel mix ratio at about 32-40:1 with a good full synthetic low flash pre mix if you are not racing motor x

verify the timing at the flywheel

[Adam Lyzwa]

On 12/16/2020 at 10:38 PM, kxrob said:

go back to standard and start from there

treat it to a new pilot jet but would go to a 48 not a 50

set air screw at 1.75 out as suggested above and put needle clip in the middle

make sure the choke circuit is clean in carb

double check your fuel mix ratio at about 32-40:1 with a good full synthetic low flash pre mix if you are not racing motor x

verify the timing at the flywheel

it’s a 4 stroke 

[mlatour]

3 hours ago, Adam Lyzwa said:

it’s a 4 stroke 

 

Then unless it's a 2019, 2020 or 2021, your bike isn't a KX250

If it's a 2005 4-stroke MX race bike, then it's a KX250F

 

Edited December 19, 2020 by mlatour

[kxrob]

On 12/19/2020 at 10:38 AM, Adam Lyzwa said:

it’s a 4 stroke 

sorry missed that bit

[Adam Lyzwa]

Just now, kxrob said:

sorry missed that bit

your good so i bought a used carb cuz i broke the mid body gasket ring thing because it started and it only ran on choke so i thought it was the mid body gasket i tried changing it and broke a lot of shit so i ordered a used card and out it on and it still doesn’t start it has low compression so i’m pretty sure it’s the reason i got my rings and eveything but i’m on vacation so once i get back i’ll put new rings on it