Poor idle on a 2007 CRF230F was caused by a plugged pilot jet. This video shows how to disassemble the carburetor and clean both the idle mixture screw and the pilot jet. It also shows the reassembly and remount of the carburetor. In addition, it shows a poor man's extension of the idle mixture screw.
00:00 Intro, tank and seat removal
01:45 Carburetor removal
03:03 Bowl, float and baffle removal
03:49 Idle mixture screw removal and clean
05:55 Refit idle mixture screw and replace
06:54 Idle mixture screw extension
09:19 Pilot jet cleaning
11:01 Carburetor reassembly
12:15 Remount carburetor
12:58 Test run