A suction tube unit connected between a cylinder block and a carburetor in a stratified scavenging engine has a suction tube for mixture made of an elastic material; and a suction tube for stratified scavenging air made of an elastic material. The suction tube for mixture and the suction tube for air have, at respective inlet ends connected to the carburetor, respective wall portions which face each other and have complementary shapes. A clearance space is provided between the wall portions of the suction tube for mixture and the suction tube for air.

A throttle body fuel injection system including a throttle body with at least one air intake, a fuel injector coupled to the throttle body at a fuel port and an annular ring coupled to the cylindrical inner wall of the air intake. The annular ring includes a primary fuel discharge orifice adjacent to the fuel port and a plurality of secondary fuel discharge orifices arranged radially around the annular ring for spraying atomized fuel into the air intake.

A throttle body fuel injection system including a throttle body with at least one air intake, a fuel injector coupled to the throttle body at a fuel port and an annular ring coupled to the cylindrical inner wall of the air intake. The annular ring includes a primary fuel discharge orifice adjacent to the fuel port and a plurality of secondary fuel discharge orifices arranged radially around the annular ring for spraying atomized fuel into the air intake.

An anti-adjusting rotary valve type carburetor includes a high speed adjustment oil needle having an eccentric hole and an idle adjustment oil needle having an eccentric hole. Also disclosed is a specialized adjustment tool having an eccentric convex platform for adjusting the high speed adjustment oil needle and the idle adjustment oil needle. Also disclosed is a high speed adjustment oil needle having an eccentric convex platform and an idle speed adjustment oil needle having an eccentric convex platform. Also disclosed is a specialized adjustment tool having an eccentric hole for adjusting the high speed adjustment oil needle and the idle speed adjustment oil needle.

An anti-adjusting rotary valve type carburetor includes a high speed adjustment oil needle having an eccentric hole and an idle adjustment oil needle having an eccentric hole. Also disclosed is a specialized adjustment tool having an eccentric convex platform for adjusting the high speed adjustment oil needle and the idle adjustment oil needle. Also disclosed is a high speed adjustment oil needle having an eccentric convex platform and an idle speed adjustment oil needle having an eccentric convex platform. Also disclosed is a specialized adjustment tool having an eccentric hole for adjusting the high speed adjustment oil needle and the idle speed adjustment oil needle.

This invention relates to an anti-adjusting butterfly valve type carburetor, comprising a kind of high speed adjustment oil needle having eccentric hole and a kind of idle adjustment oil needle having eccentric hole, and it also correspondingly discloses a kind of specialized adjustment tool having eccentric convex platform for adjusting the high speed adjustment oil needle and the idle adjustment oil needle. The invention also discloses a kind of high speed adjustment oil needle having eccentric convex platform and a kind of idle adjustment oil needle having eccentric convex platform an it also correspondingly discloses a kind of specialized adjustment tool having eccentric hole for adjusting the high speed adjustment oil needle and the idle adjustment oil needle. Compared with the prior art, the invention has the following beneficial effects: Because the high speed adjustment oil needle and the idle speed adjustment oil needle have the anti-adjusting structure, thereby ensure that the customers can not be adjust the oil flow into the carburetor freely, and then ensure that the engine is always in optimal setting state.

An anti-adjusting rotary valve type carburetor includes a high speed adjustment oil needle having an eccentric hole and an idle adjustment oil needle having an eccentric hole. Also disclosed is a specialized adjustment tool having an eccentric convex platform for adjusting the high speed adjustment oil needle and the idle adjustment oil needle. Also disclosed is a high speed adjustment oil needle having an eccentric convex platform and an idle speed adjustment oil needle having an eccentric convex platform. Also disclosed is a specialized adjustment tool having an eccentric hole for adjusting the high speed adjustment oil needle and the idle speed adjustment oil needle.

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 may include a body having a main bore from which a fuel and air mixture is discharged for use by an engine, a throttle valve head, a choke valve head and a flow directing feature. The throttle valve head may be carried by the body and is moveable between an idle position and a wide open position to control at least some fluid flow through the main bore. The choke valve head may also be carried by the body and is moveable between a first position and a second position to at least in part control fluid flow through the main bore. And the flow directing feature associated with the choke valve head or the throttle valve head may alter at least one of the velocity or direction of at least a portion of the fluid that flows in the main bore.

A method of using a throttle body fuel injection system including a throttle body with at least one air intake, an electronic fuel injector coupled to the throttle body at a fuel port and an annular ring coupled to the cylindrical inner wall of the air intake. The annular ring includes a fuel discharge orifices arranged radially around the annular ring for spraying atomized fuel into the air intake, in order to operate an internal combustion engine.