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US 5,732,685 AGranted
Fuel supply system for watercraft
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorMitsuyoshi Nakamura
Life of this patent
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AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorMitsuyoshi Nakamura
Estimating the term…
An improved fuel supply system for a watercraft engine eases the setting of fuel supply pressure in each of the carburetors of the engine. The fuel supply system includes a fuel supply line which supplies fuel to a plurality of feed branches of the fuel circuit which are arranged in parallel. Each branch communicates with one of the carburetors. The branches have equal lengths such that the flow resistance within each branch is generally the same between the branches. The fuel supply system also includes a fuel return line which communicates with a plurality of return branches of the fuel circuit. The return branches are arranged in parallel, with each return branch communicating with one of the carburetors. The return branches also have equal lengths and are arranged to have like flow resistances. This structure of the fuel circuit between the carburetors tends to isolate the carburetors from one another such that the fuel pressure in one carburetor does not affect the fuel pressure in the other carburetors. As a result, setting the fuel supply pressure of each carburetor is eased in comparison to prior fuel circuits where the carburetors are arranged in series within the fuel circuit.
A fuel circuit for an engine of a small watercraft comprising a fuel supply line communicating with a fuel source and extending into a plurality of parallel fuel circuit branches, a fuel return line communicating with each of the branches to return excess fuel to the fuel source, and a plurality of charge formers arranged in parallel with each charge former being positioned within one of the branches of the fuel circuit.
A multi-cylinder engine for a small watercraft comprising an engine block assembly including a plurality of variable-volume chambers, an induction system positioned on the side of the engine block assembly and including a plurality of charge formers, each of which supplies a fuel/air charge to one of the variably volume chambers, and a fuel circuit comprising a fuel supply line and a fuel return line, the fuel supply and returns lines separately communicating with each charger former, independent from the other charge formers.
An engine comprising an engine block including at least one variable-volume chamber, a charge former communicating with the variable-volume chamber and having an intake passage, and a fuel pump which supplies fuel to the charge former, the fuel pump being driven by pressure changes occurring within the variable-volume chamber and being located on a side of the charge former opposite the engine block with the intake passage being located between the engine block and the fuel pump.
Dependencies are inferred from the claim text.