1997 rm250 build

Need some help on 1997 RM250 two stroke tuning ,so im having low end sputtering current set up fmf fatty exhaust low jet 45 high jet 175 air screw 1.5 turn out cutaway 7. Fuel 32.1 fresh top end ,just doesnt seem to stay on ,and loads up to quickly then shuts off sputtering low end but wide open throttle it just screams and hit a power band and scares the crap out of me ,also checked the stator marking lined up for timing ,and reeds look like a good seal on the cage ,so any input will be awesome thanks ,what am i missing people