'12 klx 250s; removed snorkel and replaced air filter, now..
 

first my disclaimer - pretty much suck at mechanical stuff. willing to try things and learn, but when they don't go quite right, i don't really have the knowledge to fix 'em.

so, replaced the OEM air filter with a "no-toil" filter and at the same time, removed the snorkel. buttoned it all back up, including putting seat on (doh doh DOH). started bike up just fine, after a few seconds idle dropped to normal. while in neutral just gave it some gas (more to hear the sound difference with snorkel removed) at which point the bike promptly 'stalled' and engine off.

restarted bike, again starts right up, no problem. let it idle a few more seconds, this time with choke on, its idling fine and normal rpm. choke off, idle drops down, give it gas, and...dies.

grrr ... third time start, this time i give it very little gas and it is ok...give it a bit more, its ok, quick WOT and its ok...but there is still a slight hesitation from time i open throttle to response.

is all that normal? what did i miss? i have no other mods like jets or things like that.

thanks!

Put it all back together and see if it runs normal again. Or take the seat off and cover half of the opening to the air box and see if it runs better. Covering it will make it run richer. If your bike is stock as far as the carb goes is probably just really lean.

FYI these bikes are lean from the get go so doing those mods you did compound the issue. Get a jet kit and mod the carb regardless, best 50 bucks to spend on the bike.

Put the snorkel back in until you rejet.

ok thanks everyone, lesson learned :)

how long are you letting it warm up before you give the throttle?...you should let the bike warm up properly before you start giving sudden throttle...engine will cut out like you mentioned....

also, order a jet kit...in the mean time....remove the plastic plug from the a/f screw...make some micro turn out (richen slightly)...when i say micro, i mean mm turns...