looking for some advice on possible carb issue
 

Was riding yesterday missed a shift between 1st and 2nd when I got it into 2nd It sounded like it backfired through the carb. and died . pulled over started it and when I give it throttle it dies looking around I notice my overflow tube from the carb. was too close to my new header and melted shut . So I cut it off thinking I'm just going to ride away .No go It will start but the second I give it throttle it dies .Before I start to remove the carb. can any one think of what of what might ? Just re jetted and new needle all per Klstr's recommendations around 100 miles ago ,Bike was running really well .Full tank , Stuck float? Thanks

What bike? If it backfired is the airfilter / box / lid all ok? Did you accidentally put the choke on?

2010 kLX 250 SF . 900 miles I havn't got that far yet .It will have to wait until tomorrow. new Uni filter, lid removed on the air box. FMF Mega bomb Hdr, PC4 can re jetted to Keihin 152, DJ needle ,clip on top 2 washers glued on top ,stock spring ,, Bike was running really well, Klxster held my hand and walked me through it all .Bike wouldn't go past 65 ,now 75 and It's got more , I'm not sure what it happened I did all these mods over 100 miles ago I can go out there and start it up but give it throttle and she dies.

Well I took the carb apart and all looked fine , Reinstalled and now it won't even start ,Check the oblivious , Good spark, good fuel flow into carb , tap on carb to possibly loosen up float , no go so I pull back air filter a little and shot some starting fluid into carb and It starts ,Runs fine came back turned it off started right up ,did that a few more times starts right up ,Came back out when it was cold and no go . More starting fluid starts right up fiddling with the choke In or out no difference on Idle ,So I'm thinking that the choke is somehow faulty any Ideas ? what's the fix for that thank you