Curulewski left Styx because he wanted to spend more time with his family and have more creative control in his future endeavors. He went on to teach guitar at the Mad Music in La Grange, Illinois, Owned by Steve Paceli (AKA Stevie Starlight) and John Reda (formerly of Gus's Music, in Oak Lawn), and run a recording studio aptly called "The Studio", he also played guitar in a band called Spread Eagle, and formed the group Arctic Fox playing the Chicago area clubs. Curulewski also coached his son's baseball team, and would go into his son's Grammar School as a lunch supervisor; he would bring in his guitar and play it to the kids, much to their amazement.
Curulewski taught some of Chicago's best young guitar players including Joey Mazzuca, Dave Stulgo, Russell Leach, Hector Fernandez and many more. Many of JC's students went on to form a core group of heavy metal guitarists in Chicago. Curulewski became very active in the mentoring of young bands in the western suburbs of Chicago; not only teaching guitar but coaching on performance and supplying support for live appearances and recording.
Curulewski died on February 13, 1988, from a brain aneurysm. He is survived by his former wife and their son.