Lefebvre first got involved in motorsports via drag racing; and became a prominent tuner of two-stroke race bikes in Canada in the mid-1970s, working for several top riders, including Robbie Meiklejohn. He would later join Meiklejohn in the 1980s, the popular pair running Rocket Motorcycles in Toronto.
After a brief stint with the famous racing Steinhausen family of Germany on the European "Circus" tour, Lefebvre returned to Canada and worked with Barrie top gun Gary Collins on Yamaha TZ250, 373 and 750 equipment, then joined rising star Alan Labrosse on the AMA 250 G.P. tour 1983. Lefebvre also built engines for Roland Reidmann, father of current Canadian CSBK tour star Kenny Reidmann.
Instrumental in the developing careers of Kathleen Coburn and G.P. ace Steve Galbraith, Lefebvre also tuned for the works Rothmans-Honda Superbike squad, looking after former Canadian National Champ Paul MacMillan. MacMillan and Lefebvre also found success with Yoshimura-Suzuki equipment for Team Ciampini.
Lefebvre was also successful with occasional club racing outings, including a VRRA victory aboard Meiklejohn's famous Honda CR750 kit racer at Shannonville's Vintage Festival in August of 1983.