The TU has a single overhead cam (SOHC), unsleeved, four-stroke engine with chain-drive, a standard riding posture and styling resembling the Universal Japanese Motorcycle (UJM) of the 1960s and 1970s.

The second generation TU debuted at the 37th Tokyo Motor Show 2003, described at the time by Suzuki as: The bike was formally introduced to the Japanese domestic market in December 2003 for model year 2004 as the ST250 and ST250 E-Type, the latter having a higher level of trim, including a two-tone fuel tank, polished engine, chromed exhaust pipe, CDI ignition and a kick starter as well as electric start.

The coating, marketed as Suzuki Composite Electro-chemical Material or SCEM, is nickel-phosphorus-silicon-carbide based, reducing weight (by eliminating a steel liner) and improving heat transfer, allowing for tighter and more efficient piston-to-cylinder clearance.

[10] Specifications include a five speed transmission with cable-actuated clutch,[11] electric starting (with kickstarter in the JDM), clutch and side stand interlocks (cut-outs), electronic ignition system, maintenance free battery, tubular steel frame with load bearing (stressed member) engine,[8] rear drum brake and front 275mm dual-piston caliper disk brake by Tokico, chrome-plated locking gas cap, passenger pillion separate from the driver's seat, plastic front and rear fenders, factory equipped tool kit (under the right side panel),[10] helmet lock,[6] tapered chrome muffler,[10] and chrome wired wheels.

"[14] Describing the TU250x, author Pete Brissette of Motorcycle.com wrote that Suzuki had "returned to the simple formula of the UJM, and with it brought back the pleasures of riding a friendly, straightforward motorcycle.