BMW Motorrad (Motorcycles) of Germany is introducing dual ignition for its R 1100 S, R 1150 GS, R 1150 R, R 1150 RS and R 1150 RT boxer twin-cylinder models. The changeover in production began last November, and is being conducted model by model. The program is slated to be completed early this year.
BMW says the dual ignition will improve exhaust emission levels. This change is designed to prepare the engines for the new exhaust emission legislation contained in EU 2 standards and, for the future, the stricter EU 3 regulations.
According to BMW, the key effect of the dual ignition system will be to increase stability and improve the uniformity of combustion in all the operating ranges of the engine.
As a bonus, it has also been possible to increase the efficiency of the engines still further, which is reflected in a slight reduction in fuel consumption. Claimed peak engine power output and torque remain the same for all models.
The dual ignition system requires an additional hole in the cylinder head for the second spark plug as well as another ignition system which is capable of providing the second spark.
BMW reports that the position selected for the second spark plug in the lower section of the combustion chamber results not only in optimum combustion, but also means that it is possible to fit the spark plug and lead in such a way that it is relatively well hidden. An external indication for all engines that are fitted with dual ignition is the redesigned cover for the plug and the decal ‘2-spark’.
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