The weight of the previous year, 458 lbs (207 kg), was maintained while adding the water cooling. Also to be noted this was the last year of the "Power Jet" which came stock on the carburetors since 1989. These were noticeable by the short fuel line to the left of the carburetor, running the length from the fuel bowl to the top of the bell housing. Basic function of the power jet was the smooth out fuel delivery from 9.5k- 10k rpm all the way to the rev limiter. However, these jets were blanked out on the US models but were fully functional for Canadian buyers and other countries. The water cooled bikes would not be available to the US until 1993. Fourth generation: 1994 A comprehensive redesign, still using the same basic frame and engine architecture, resulted in a bike 22 lb (10 kg) lighter, down to 436 lb (19 kg). The following year would be the last for the double downtube / angled top tube frame design that had originated on the 1985 GSX-R. Fifth generation: 1996 The old frame design, a unique signature of the GSX-R was dated. By 1996 all of the manufacturers were using aluminum frames, and most of them were stiffer and lighter than the Suzuki frame, and featured large beams running in a straight line from the steerer tube to the swingarm pivot. The 1996 followed this principle, and along with the new frame a completely revised engine was used. As a result of this comprehensive redesign the GSX-R began its return to the front of the production racer pack, finally beginning to achieve the AMA Superbike domination it had been designed for a decade previously. The new architecture allowed the GSX-R to win an impressive 10 of 11 consecutive AMA Superbike championships beginning in 1999. The 1996 GSX-R was a return to the original formula, with an emphasis on light weight, not just power. Weight was back down to an impressive 394 lb (178 kg). Even though later models also used the Suzuki Ram Air Direct system, GSX-R's from 1996-1999 became known as the SRAD models. Sixth generation: 2000 The year 2000 again saw a total redesign of the engine, now with dual throttle valve electronic fuel injection. A new frame was also introduced in this model that was lighter, and had a longer swingarm than the previous model. Performance was improved,