The Suzuki GSX-R 750 1991 brings to 750cc class production motorcycles an all-around superiority won in successful factory racing actions and proven in a wide range of production endurance racing events. Powerful, circuit-bred performance features like engine improvements straight out of the factory team’s race shop, rigid inverted front fork and Suzuki’s unique progressive link rear suspension all cradled within an aluminum-alloy frame and swingarm whose efficiency has been proved with modified racing engines. The Suzuki GSX-R 750 1991 is another Suzukisuccess in efficient application of racing technology — technology that’s made the Suzuki GSX-R 750 1991 Mthe dominant force in 750cc Stock Production-based racing — to street bikes. It’s direct access racing technology in action.
The Suzuki GSX-R 750 1991 gained 15 kg more than the previous model! Some Suzuki sales brochures didn’t even bother to quote a weight figure. The weight factor alone sends this bike to the back of the GSX-R pack. The most notable feature of the “M” are the faired in headlamps and a slanted nose, both of which were designed to reduce front drag, with distinctive headlight cover and running lights. Also fitted was a new larger seat and new rear body work that featured twin tail lamps. New aerodynamic fairing with slanted nose to reduce frontal drag, with distinctive headlight cover and running lights. The seat was enlarged and twin tail lamp design graced the backend.
This was the last GSX-R to use the oil-cooled SACS engine (except for US). Internal engine changes included a new valvetrain that used one dedicated cam lobe and rocker arm (finger follower) per valve (previous models used one lobe and one forked rocker per two valves). Valve clearance (lash) was now adjusted with shims (previous models used a screw and nut). The cam duration and indexing changed slightly as well as the porting according to a magazine article. The rear tire width was increased to a 170 mm section width. The gauges also changed to white colored needles (previously amber colored). Horsepower increased by 1 to 116 hp. The oil-cooled SACS engine received internal refinement of adopting one rocker arm per valve from the previous of one per two valves, stronger valve springs and an exhaust cam with 7 degrees less duration to give 116 hp.
The latest GSX-R750 749cc powerhouse features cylinder head designs straight from the factory racers:
Valve seats are smoothly blended with reshaped intake ports for better cylinder charging and higher torque.
Use of lightweight, single rocker arms to open each valve, and use of small shims to adjust valve lash, reduces inertial mass and mechanical losses.
Lightweight pistons with light, thin rings efficiently reduce friction and resist fluttering even at peak rpms.
Suzuki Advanced Cooling System (SACS), combined with air cooling, efficiently carries engine heat away to the high- capacity curved Radial Flow cooler.