400EX backfires on acceleration

[PINKSTEEL]

My 400ex was running fine then starting backfiring on acceleration and now it has very weak to no spark.

Please help. Think it might be the stator.

[PaRedneckRiders]

Well usally backfiring on acceleration is because its running to rich

Then no spark that vould b a completly different problem if u wanted to replace the stator u could then if its still backfiring on acceleration but has good spark its running to rich and u should adjust a/f screw and prob jets