The tightening global emissions restrictions are pushing engineers to find create ways to generate more power while still meeting the tigher Euro 5 emission standards to be implemented next year. Put simply, for a motorcycle to comply with the Euro 5 emission standards, it has to cut on carbon monoxide (CO), hydrocarbons (HC) and oxides of nitrogen (NOx). Even after 20,000 kilometers, it still has to meet Euro 4 standards.
Other motorcycle manufacturers are already eyeing electric powerplants as the simplest solution. India is requiring all motorcycles 150cc and below sold domestically to be all-electric by 2025.
Honda, however, seems intent of refining the internal combustion engine by adding an additional spark plug, particularly the one for the CRF 250L and CRF 250L Rally.
On a patent application submitted by Honda, the design clearly suggests an additional spark plug in the CRF's engine to produce a cleaner burn. This is not a first in motorcycle engine technology. In fact, there are already a number of motorcycle models currently in production that have twin-spark technology.
It has also been proven that adding an additional spark plug not only reduces emissions but also helps increase the power output and efficiency of the engine. The less unburned fuel in the combustion chamber, the lower its emissions.
The patent also suggests that the existing top cylinder spark plug of the CRF will be complemented by an angled spark plug on the cylinder head's left bank, just below the fuel injector.
Since electric motorcycle technology is still far from perfect in terms of reliability and recharging times, twin-spark might be the way to go in the foreseeable future of motorcycles.