The S3 Thunderbolt sport-touring model was produced from 1997 through 2002, along with a mechanically identical S3T "Touring" model that ran through model year 2000. The 1,203 cc air-cooled V-Twin engine was mounted as a stressed member in a tubular frame. The powerplant output 91 hp (68 kW) in 1997 and jumped to 101 hp (75 kW) in the following years due to revised cam profiles and the new Thunderstorm cylinder heads. While the bike's overall look was the same throughout the model run, there were significant changes made in 1999 that set it, and later models, apart from the 1997 and 1998 bikes. The early bikes used a rectangular section steel rear swingarm, WP Suspension front forks and rear shock, a Keihin 40 mm CV carburetor, and a Performance Machine six-piston front brake caliper. Beginning in 1999 a new cast aluminum rear swingarm was utilized along with Showa front suspension forks and rear shock. The front brake caliper, while still a six-piston unit, was now made by Nissin. The most technological change came in the new Dynamic Digital Fuel Injection (DDFI) system, replacing the old carburetor.
The S3 featured a half faring that surrounded the headlight and gave decent wind protection for the rider's torso. The S3T model then added lower fairing extensions that gave better wind protection to the rider's legs. The S3T also featured hard saddlebags that could be color-matched to the bike color and were available in either "wide" for maximum storage, or "narrow" for a lighter feel. In addition to the lower fairings and the saddlebags, the S3T also came with a taller handlebar for a more upright, relaxed riding position. Each of the parts that set the S3T apart were available as accessories for the standard S3 model.[better source needed][23]