yep, its timing. have you messed with the flywheel and stator at all. cdi wouldnt have anything to do with the timing. your either advanced or retarded a few degrees. pull your flywheel and check your stator plate, maybe your screws that hold it in place could of loosened up and it moved just a bit, them rebounding kickers can be very bad on the bottom of the foot, i know!!!! also like already said, check the flywheel key to make sure it hasnt broken off. and just a tip....next time quad issues are posted in quad central.
1985 KXT 250 Tecate - kx cylinder, kx ignition, bassani headpipe, answer silencer, v-force reeds, 38mm airstyker carb, +2 franks swinger, raptor rear shock.
1996 YSF240 Blaster - maxxed out!!!
Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting "HOLY SH-T, what a ride!"