2003 KLX400SR backfire no idle

I've read so many posts on this and they seem to say clean the carb. Well, I've had the carb off 3 times and cleaned it. Taken every jet out, cleaned all the pathways. I never did see anything clogged. Bike still will not idle w/o being choked. It also backfires at a constant throttle. This all happened after sitting over the winter. I would think something was clogged, but no signs of it. Also ran SeaFoam through a tank of gas. Same result. Not sure where to go next??

Replace the pilot jet. Cleaing it is a waste of time.

Replace it with a new stock jet or an aftermarket of a different size? No mods at all to this bike. Thanks

maybe a bad intake boot? a crack or tear?

or the passageways of the idle circuit rather than the actual jet.

Boot looks ok-thanks. I think I'll give one more shot at cleaning things out. Probably let the whole darn carb sit in cleaner over the weekend in case it is in the passages!

Depending on the type of cleaner used be careful you don't mess up any rubber parts.

You know, doing the same thing over and over and expecting different results is not sane. Save the time and effort and simply put in a new pilot jet.

or the passageways of the idle circuit rather than the actual jet.

This is where I would look. I went thru the same problems 2 years ago when I bought my bike and one of the passageways was plugged.

My sanity is frequently questioned...

Well, after soaking the whole thing for about 2 hours and blowing everything out with the air compressor, paying special attention to the passageways, it seems pretty good! I drilled the plug out to get to the a/f adjustment and with it about 3 turns out I think it's much better. Thanks for your help.

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