Development of Advanced Digital Engine Control System for Outboard Motors



Small Engine Technology Conference & Exposition
Authors Abstract
A new 3.1 liter two-stroke-cycle V6 engine has been developed for the big power outboard motor VX model.
This engine has the complex digital engine control system which was developed for the essential properties of high output, all-round running performance, and quick start. The properties are required to meet the larger marine engine market demand, and must be backed up with positive reliability.
The system comprises a multipolar alternator with ample capacity of 12V 35A to satisfy the demands from larger outboard motor, and a CDI unit to control the spark timing and fuel enrichment, and also to provide the diagnostic function.
Necessary data for the system is input by the sensors monitoring crankshaft position, throttle angle, knocking, oil level, trim angle, and coolant temperature. Based on these data, the system outputs: control signals for spark timing, fuel enrichment, and oil feed pump operation; engine rpm and oil display; over heat warning; and diagnostic function.
Also the system is specially constructed to fit for the severe environments in which marine engines are normally used: water-proof direct-in connecter with the wet environment; back-up power system under low battery condition; electrical noise proof design.
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Kojima, A., and Umemoto, H., "Development of Advanced Digital Engine Control System for Outboard Motors," SAE Technical Paper 911227, 1991,
Additional Details
Nov 1, 1991
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Technical Paper