Krauchanka moved into decathlon competitions in 2004 and, after setting a best of 7963 points to win the national junior title, he broke the championship record at the 2004 World Junior Championships in Athletics, collecting 8126 points with a series of personal bests. He broke the national junior record in heptathlon at 2005's Tallinn combined events meeting with 5929 points. He placed 13th at the high-profile 2005 Hypo-Meeting before winning his second major junior title at the 2005 European Athletics Junior Championships. In 2006 he again broke the 8000-point barrier, coming eleventh at the 2006 Hypo-Meeting, and placed third at the European Cup Combined Events.