As far as i know the 04 kx250f use kyb,so should fit,as kyb on kx,s usually use the same size fork where they bolt on the clamps.I know the kx45013 share the same size forks were the clamps go as a kx 250 01 forks which indicates most kyb should swap over.Late model kx250f use showa forks,could be 06 onwards ?The top of the showa forks,were the top clamp bolt on are usually slightly smaller ,but could be made to fit also ,as i am sure some of the guys on this site have done?