Powerplants and Fueling
The 600 cc and 900 cc version are both based on the GSX1100R bottom end – a 16-valve inline-four, four-stroke, water-cooled unit. The RF has smaller carburetors (Mikuni BDST36 36 mm downdraughts), and smaller valves. This results in a smoother power delivery and a more usable engine. The engine is canted forwards in the frame by 19 degrees to allow for a lower center of gravity, and allows the fuel air mixture to be "dropped" into the cylinders on the intake stroke. This also allows for a 6-litre airbox. The 900 cc engine has a redline of 12,000 rpm (although maximum power is achieved before this at 10,000 rpm), and the 600 cc engine has a slightly higher 13,500 rpm redline.
There is no fuel gauge, however a "fuel low" light is present, which gets brighter as the reserve level is approached. Filling up at the lowest brightness of the light will result in only half the fuel capacity of the motorcycle being used. The bike has a 4 L (0.88 imp gal; 1.1 US gal) reserve, switched to with the usual fuel cock on the left hand seat unit fairing.
The 400 cc version is somewhat different, and uses the engine from the Suzuki GSF400 fitted with 32 mm Mikuni carburetors.
The 900 uses a stainless 4-2-1 exhaust header while the 600 and 400 bikes use steel 4-1 headers. The later 600, and all the 900 versions use a tri-bolt can fitment. The earlier 600 and all 400 RF bikes use a slip on with link pipe system, with a join below the center of the bike.
Read more about this topic: Suzuki RF400R