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Development of a Small Motorcycle EFI Retrofit System
Published November 03, 2009 by Society of Automotive Engineers of Japan in Japan
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Carbureted small displacement motorcycles are the most common form of road transport in Asia. Small displacement motorcycles have historically been low-cost and low-tech. In order to achieve the best overall performance, economy and emissions, a more sophisticated fuel injection system is required. To address the fuel consumption and emissions of existing “legacy” vehicles, we have developed an Electronic Fuel Injection (EFI) retrofit for common small motorcycles in Asia. The system leverages existing components as much as possible allowing focus on integration into the host vehicle and overall system tuning. This paper details the overall system design, modeling, component selection and system tuning of a 120 cc single cylinder four stroke EFI retrofit kit. The target vehicle is tested on dynamometer with stock carburetor settings, and with the EFI kit. The EFI system reduces fuel consumption by approximately 10%, HC emissions by 55%, CO emissions by 96% while doubling the NOx emissions and matching the carbureted system's power.
CitationLai, T. and GITANO-BRIGGS, H., "Development of a Small Motorcycle EFI Retrofit System," SAE Technical Paper 2009-32-0034, 2009.
- Birch Brian J. and Amann Manfred, Electronic Fuel System Development for Air-Cooled Motorcycles, SAE 2004-32-0059
- Heng TEOH Yew, GITANO-BRIGGS Horizon Dr., MUSTAFA Khairil Faizi, Performance Characterization of a Direct Injection LPG Fuelled Two-Stroke Motorcycle Engine, SAE 2008-32-0045
- Ricardo Inc. 2007, WAVE User's Manual: Basic Manual, Burr Ridge, I1, USA
- Heywood John B., Internal Combustion Engine Fundamentals (1981)