# US 4,394,331 A · Carburetor

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,394,331 A
- Document ID: US4394331A
- Status: Granted
- Kind: A
- Application number: 06/238,632
- Filed: 1981-11-06
- Granted: 1983-07-19
- Earliest claimed: 1981-11-06
- Assignees: Honda Giken Kogyo Kabushiki Kaisha
- Inventors: Yousuke Okabe; Osamu Shoji
- Web page: https://patentgrep.com/patent/US4394331A

## CPC

- F02M 3/12: Passageway systems
- F02M 1/16: Other means for enriching fuel-air mixture during starting; Priming cups; using different fuels for starting and normal operation
- Y10S 261/08: Carburetor primers
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A carburetor for internal combustion engines adapted to operate normally with an alcoholic fuel. The carburetor has a slow fuel passage communicating with an idle port and a by-pass port both of which open to an intake bore at a portion of the latter around a throttle valve, a cup-shaped member disposed in a float chamber at a level beneath the level of the fuel in the float chamber and defining therein a downwardly opened space. A primary jet leading to a primary nozzle and a secondary jet leading to a secondary nozzle, which are known per se, are arranged to open, respectively, to an uppermost portion and an intermediate portion of the space in the cup-shaped member. The float chamber is communicated through a float valve of the known type with a main fuel tank storing an alcoholic fuel as the main fuel, while the space in the cup-shaped member is communicated, through a metering pump, with an auxiliary fuel tank storing therein gasoline as the starting fuel.

## Claims

### Claim 1

In a carburetor including an intake bore having a venturi portion therein, a throttle valve disposed in said intake bore at the downstream side of said venturi portion, a primary nozzle opening to a portion of said intake bore between said throttle valve and said venturi portion, and a secondary nozzle opening to said venturi portion, said primary nozzle and said secondary nozzle being in communication with a float chamber through a primary jet and a secondary jet, respectively;
an improvement which comprises: a slow fuel passage shunting from a portion between said primary nozzle and said primary jet, said slow fuel passage being communicated with an idle port and a by-pass port both of which open to said intake bore in the vicinity of said throttle valve; a cup-shaped disposed beneath the level of the fuel in said float chamber and defining therein a downwardly opened space, said primary jet opening to an uppermost portion of the space in said cup-shaped member while said secondary jet opening to an intermediate portion of the space in said cup-shaped member; a main fuel tank storing an alcoholic fuel therein and communicating with said float chamber through a float chamber; and an auxiliary fuel tank storing gasoline therein and communicating with the space in said cup-shaped member through a metering pump.