Two Spark Technology

BMW is introducing a two spark ignition system on 2004 model year R1100 S, R1150 GS, R1150 R, R1150 RS and R1150 RT models.

The effect of a two ignition system is to improve the uniformity of combustion throughout the engine's operating range and represents a solution to the fundamental conflict between the need for the lowest possible emission of pollutants and smooth running throughout the motorcycles range of useable RPM. Engine power output and torque remain the same for all models, but as a bonus, the efficiency of these engines has been increased, with a slight reduction in fuel consumption.

The two ignition system for combustion engines has existed for many years and BMW has a long tradition of applying such systems to aircraft engines. The technical principle is simple - instead of one spark plug in the combustion chamber there are two, which are sparking in parallel, and used to ignite the fuel-air mixture. The system requires an additional bore in the cylinder head for the second spark plug as well as a more powerful ignition system capable of providing the extra energy needed to create a second ignition spark.

This change in specification was incorporated to further improve the exhaust emission quality of the boxer twin. BMW is looking forward in preparing the boxer engine to meet the requirements of the new European exhaust emissions legislation known as EU 2 and for the future, EU 3. Meeting the requirements for EU 2 and EU 3 also allow these engines to meet the California emission requirements slated for 2008.