An engine having a linkage assembly, the linkage assembly having a governor lever, a governor shaft, and a throttle link. The governor lever couples the governor shaft to the throttle link. The governor lever is configured to adjust the relative position between the throttle link and the governor shaft. The governor lever has a primary arm and a secondary arm, the primary arm being movable with respect to the secondary arm. The primary arm and secondary arm are secured via a fastener which prevents relative motion between the primary and secondary arms.

An intake port is configured such that a center position of an intake upstream side opening is offset to one side in a juxtaposition direction of intake downstream side openings with respect to a center position between the intake downstream side openings in the juxtaposition direction as viewed in plan of a cylinder head. An injector is configured such that a fuel injection center axial line is inclined to the other side in the juxtaposition direction with respect to a center axial line of the intake upstream side opening as viewed in plan of the cylinder head.

An intake structure of the present invention is applied to a multi-cylinder engine including an electrically controlled throttle integrally including a throttle valve configured to adjust an amount of air to be supplied to the engine and an electronic control unit configured to control the throttle valve. The engine intake structure includes: an air cleaner configured to purify the air; and an intake manifold configured to distribute the air purified by the air cleaner to an intake port of each cylinder of the multi-cylinder engine. The electrically controlled throttle is attached to the intake manifold such that the electronic control unit is separated outward in a radial direction of an engine rotation shaft.

An engine having a linkage assembly, the linkage assembly having a governor lever, a governor shaft, and a throttle link. The governor lever couples the governor shaft to the throttle link. The governor lever is configured to adjust the relative position between the throttle link and the governor shaft. The governor lever has a primary arm and a secondary arm, the primary arm being movable with respect to the secondary arm. The primary arm and secondary arm are secured via a fastener which prevents relative motion between the primary and secondary arms.

An intake structure of the present invention is applied to a multi-cylinder engine including an electrically controlled throttle integrally including a throttle valve configured to adjust an amount of air to be supplied to the engine and an electronic control unit configured to control the throttle valve. The engine intake structure includes: an air cleaner configured to purify the air; and an intake manifold configured to distribute the air purified by the air cleaner to an intake port of each cylinder of the multi-cylinder engine. The electrically controlled throttle is attached to the intake manifold such that the electronic control unit is separated outward in a radial direction of an engine rotation shaft.

A first throttle body and a second throttle body include valve rotation devices that independently drive respective throttle valves. The first throttle body and the second throttle body are arranged such that the respective valve rotation devices have states rotated around respective bore central axes to cause respective throttle valve rotation shafts to have angles with respect to straight lines parallel to a crankshaft in an engine top view.

A first throttle body and a second throttle body include valve rotation devices that independently drive respective throttle valves. The first throttle body and the second throttle body are arranged such that the respective valve rotation devices have states rotated around respective bore central axes to cause respective throttle valve rotation shafts to have angles with respect to straight lines parallel to a crankshaft in an engine top view.

An engine having a linkage assembly, the linkage assembly having a governor lever, a governor shaft, and a throttle link. The governor lever couples the governor shaft to the throttle link. The governor lever is configured to adjust the relative position between the throttle link and the governor shaft. The governor lever has a primary arm and a secondary arm, the primary arm being movable with respect to the secondary arm. The primary arm and secondary arm are secured via a fastener which prevents relative motion between the primary and secondary arms.

A coil-over throttle return spring device mounts onto the exterior of the carburetor and allows the user to adjust the throttle tension without having to remove the device from the carburetor. The throttle tension is adjusted by moving the ring along the length of the body to lengthen or shorten the spring. A coil-over throttle return spring device kit comprises the device and a bracket and hardware used to easily mount onto various size carburetors. The bracket and hardware allows for adjustability depending on the size of the engine and length of cables. A method of installing a coil-over throttle return spring device kit onto a carburetor and a method of adjusting the throttle tension.

Disclosed is a blowby gas treatment device for an internal combustion engine with a supercharger, the blowby gas treatment device comprising: a fresh air introduction passage wherein one end of the fresh air introduction passage is connected to an upstream side of the supercharger and the other end is communicated with a crankcase of the internal combustion engine; a first blowby gas passage wherein one end of the first blowby gas passage is connected to a venturi part provided in an upstream side of the supercharger in the intake passage and the other end is communicated with the crankcase; a first check valve being interposed in the fresh air introduction passage and preventing a flow from the crankcase side to the intake passage side; and a second check valve being interposed in the blowby gas passage and preventing a flow from the intake passage side to the crankcase side.