According to the search results, there is no information about the weight of ksi as a unit of measurement. However, the search results do provide information about the weight of KSI, the YouTuber and boxer, in the context of his fight against Tommy Fury. KSIs weight is listed as cruiserweight, which is a weight class in boxing that ranges from 175 to 200 pounds. In his fight against Tommy Fury, KSI increased his weight to 185 pounds.