[230s aren't bad]

hi there, I'm looking for some help regarding my 2003 CRF 230F coughing, popping, and backfiring. the coughing sound sounds to be coming from the carburetor. all the other sounds are coming from the exhaust (pops and backfires) starting to think I should just get a new jetting kit? what do you think?

[Aussiecrf230]

How old is the fuel?
If you are lucky fresh fuel may fix problem.

Maybe not a jetting kit but definitely clean up what is there.
If it has sat for any length of time the jets and passageways will be blocked with varnish or jelly.

Also make sure tank can breath.

The screen on the fuel tap can also dissolve/melt and restrict fuel flow so check flow at the carby.

[230s aren't bad]

hey, its been a minute (3 years) but I still have this problem, its definitely not a old fuel problem, but thank you for the suggestion. I have shifted my train of thought back to the jets. I have a 135 main and a 42 slow, with the stock needle set to the 2nd from bottom slot. the bike will run with the mixture screw set all the way in so its too rich right? then I should move the needle up one spot to make it leaner. but one thing is bugging me, and that's that everywhere online it says that coughs, backfires, and pops are caused by the bike being too lean. am I on the right track or what? I ride the bike about 5 times per season over the 3 years and I haven't noticed any real problems, its just that nobody else's bike does it.

climate:
~300-600 feet altitude
~45-75 degrees Fahrenheit