THE TECHNOLOGY BEHIND THE ENGINE DESIGN
The liquid-cooled 125cc DOHC four-valve engine of the GSX-S125 could be used as a college textbook, an example of how to develop top performance with a compact and efficient engine. The goals of Suzuki engineers were combustion efficiency, engine balance and fuel economy.
There is a distinct connection between the GSX-S125 and the GSX-R series. In fact, both engines adopt a super-square design, with an increased bore and reduced stroke, and boast a bore-to-stroke ratio of 1.501:1 for the GSX-S125 and 1.576:1 for the GSX-R600, respectively.
The high bore size (62 mm) allows the housing of two 24 mm diameter intake valves, while the exhaust valve diameter measures 21 mm. Due to the engine size, the shape of the combustion chamber has been improved so as to increase the compression ratio, overall performance and range.