Note: This is the pre-re skill_cast_db
https://rathena.svn.sourceforge.net/svnroot/rathena/trunk/db/pre-re/skill_cast_db.txt
// Structure of Database:
// SkillID,CastingTime,AfterCastActDelay,AfterCastWalkDelay,Duration1,Duration2,Cool Down
//-- CR_ACIDDEMONSTRATION
490,1000,1000,0,0,0,0
Change it accordingly.