426 dies when choke i pushed in

[99tonkatruck]

Hi all first post here, I have searched for the past 2 hours and cant find the answer please help. I have a 2001 yz426f and normal cold start up with choke out. It starts first or second kick no prob. After letting it warm up a bit i push choke back in and bike dies. Do this 2 or three more times, same result. I then rode around easy for 5 minutes with choke pulled out, bike now good and warm, push choke in and bike dies, i dont get it. I have messed with idle bringing it up and down, bike still dies.

[rickallen124]

Your pilot jet is probably plugged.

[426 NOOB]

Hi all first post here, I have searched for the past 2 hours and cant find the answer please help. I have a 2001 yz426f and normal cold start up with choke out. It starts first or second kick no prob. After letting it warm up a bit i push choke back in and bike dies. Do this 2 or three more times, same result. I then rode around easy for 5 minutes with choke pulled out, bike now good and warm, push choke in and bike dies, i dont get it. I have messed with idle bringing it up and down, bike still dies.

pilot jet for sure

[642MX]

These guys are right, pilot circuit.

[desert-rat660]

mixture screw could have fallen out.

[99tonkatruck]

Thanks guys i pulled the carb off and cleaned it very well, the bike runs great now.