The younger brother of four-time NASCAR Sprint Cup Series race winner Joe Nemechek, John followed his brother into racing, participating in his first race at the age of twelve in an 80 class dirtbike race.
After a quick progression to the 250cc class, he moved onto mini-stock cars, where he raced against his brother, and eventually late-model stocks.

When he was not racing, Nemechek served as the front-tire changer on Joe's pit crew, and was on Joe's 1992 NASCAR Busch Series championship-winning team.
He would begin attempting NASCAR races himself, and ran one Busch race at IRP in 1994.
He finished 30th after his No.
89 Chevrolet suffered an engine failure.
The following season, he began racing in the new Craftsman Truck Series, driving at first for Redding Motorsports, and then for his brother's NEMCO Motorsports.
In the first year of competition, Nemechek ran 16 races and had two top-ten finishes.
He followed that up with two more top-tens in 1996 and a thirteenth-place finish in points, running a single truck he built himself titled the War Wagon under his own team, Chek Racing.
The younger brother of four-time NASCAR Sprint Cup Series race winner Joe Nemechek, John followed his brother into racing, participating in his first race at the age of twelve in an 80 class dirtbike race. After a quick progression to the 250cc class, he moved onto mini-stock cars, where he raced against his brother, and eventually late-model stocks.
When he was not racing, Nemechek served as the front-tire changer on Joe's pit crew, and was on Joe's 1992 NASCAR Busch Series championship-winning team. He would begin attempting NASCAR races himself, and ran one Busch race at IRP in 1994. He finished 30th after his No. 89 Chevrolet suffered an engine failure. The following season, he began racing in the new Craftsman Truck Series, driving at first for Redding Motorsports, and then for his brother's NEMCO Motorsports. In the first year of competition, Nemechek ran 16 races and had two top-ten finishes. He followed that up with two more top-tens in 1996 and a thirteenth-place finish in points, running a single truck he built himself titled the War Wagon under his own team, Chek Racing.
John Nemechek