A carburetor with rotary valve includes an idle adjustment needle with an eccentric hole, accordingly a special adjustment tool used for idle adjustment needle has an eccentric boss; a carburetor with rotary valve includes an idle adjustment needle with an eccentric boss, accordingly a special adjustment tool used for idle adjustment needle has an eccentric hole. The idle adjustment needle must be cooperated with the special adjustment tool to carry out the adjustment, thus non-professional user can not casually adjust the fuel oil needle without the special tool, so that the engine can be maintained in the best setting condition to ensure the engine exhaust to meet the environmental protection requirement.

A carburetor fuel flow control device having an elongate annular body received in a cavity with an inlet in its side-wall communicating with a fuel supply passage and an outlet downstream of the inlet and adjacent to an end of the body, and a needle valve with a metering portion adjacent one end rotatably and slidably received in the body with the metering portion at least partially lapping or blocking the inlet to change the effective flow area of the inlet in response to generally axial movement of the needle valve relative to the inlet.

A carburetor fuel flow control device having an elongate annular body received in a cavity with an inlet in its side-wall communicating with a fuel supply passage and an outlet downstream of the inlet and adjacent to an end of the body, and a needle valve with a metering portion adjacent one end rotatably and slidably received in the body with the metering portion at least partially lapping or blocking the inlet to change the effective flow area of the inlet in response to generally axial movement of the needle valve relative to the inlet.

A throttle valve device ideal for small, inexpensive implements is provided. The throttle valve device having a damping member for slowly closing a throttle valve. The throttle valve device (1) has a throttle valve (4) that is fixed to a throttle shaft (5) pivotably supported in an air intake passage (2) and that is urged towards the closed direction, the throttle valve (4) adapted for adjusting the amount of air passing through the air intake passage (2). A through-bore (31) penetrating a shaft bore of the throttle shaft (5) is formed in a body, and a damping member (8) having frictional capabilities is inserted into and supported in the through-bore (31) in a state of pressing against the throttle shaft (5) inserted through the shaft bore (51).

A carburetor with rotary valve includes an idle adjustment needle with an eccentric hole, accordingly a special adjustment tool used for idle adjustment needle has an eccentric boss; a carburetor with rotary valve includes an idle adjustment needle with an eccentric boss, accordingly a special adjustment tool used for idle adjustment needle has an eccentric hole. The idle adjustment needle must be cooperated with the special adjustment tool to carry out the adjustment, thus non-professional user can not casually adjust the fuel oil needle without the special tool, so that the engine can be maintained in the best setting condition to ensure the engine exhaust to meet the environmental protection requirement.

A carburetor with rotary valve includes an idle adjustment needle with an eccentric hole, accordingly a special adjustment tool used for idle adjustment needle has an eccentric boss; a carburetor with rotary valve includes an idle adjustment needle with an eccentric boss, accordingly a special adjustment tool used for idle adjustment needle has an eccentric hole. The idle adjustment needle must be cooperated with the special adjustment tool to carry out the adjustment, thus non-professional user can not casually adjust the fuel oil needle without the special tool, so that the engine can be maintained in the best setting condition to ensure the engine exhaust to meet the environmental protection requirement.

A fuel regulator includes a limit cap which is attached to a needle valve which is inserted into a regulation hole. In an inner peripheral surface of a second hole portion of the regulation hole, a restriction groove and a guide groove which extends from the restriction groove through an outer surface of a main body portion in an axial direction of the second hole portion are formed. A projecting portion which is inserted into the restriction groove is formed on an outer peripheral surface of the limit cap, and the projecting portion is capable of passing through the guide groove, and in the main body portion, a cast hole which extends from the restriction groove through the outer surface of the main body portion in a direction intersecting the axial direction of the second hole portion is formed.

A fuel regulator includes a limit cap which is attached to a needle valve which is inserted into a regulation hole. In an inner peripheral surface of a second hole portion of the regulation hole, a restriction groove and a guide groove which extends from the restriction groove through an outer surface of a main body portion in an axial direction of the second hole portion are formed. A projecting portion which is inserted into the restriction groove is formed on an outer peripheral surface of the limit cap, and the projecting portion is capable of passing through the guide groove, and in the main body portion, a cast hole which extends from the restriction groove through the outer surface of the main body portion in a direction intersecting the axial direction of the second hole portion is formed.