A breather apparatus for an engine includes a breather chamber, one side portion and other side portion of the breather chamber, and a bottom face of the other side portion. The breather chamber is formed, along substantially half a circumference of a cylinder bore, in a cylinder block. The one side portion of the breather chamber is provided with a blow-by gas introduction hole leading blow-by gas in the crank chamber to the breather chamber and a one-way valve opening and closing the blow-by gas introduction hole. The other side portion of the breather chamber has a pipe connection hole connecting a breather pipe to the breather chamber and with a breather oil return passage. The bottom face of the other side portion projects into the crank chamber to a level lower than a bottom face of the one side portion.

A small air-cooled internal combustion engine includes an aluminum engine block including a cylinder extending along a longitudinal cylinder axis and a block mounting surface, a piston configured to reciprocate within the cylinder, a crankshaft coupled to the piston and configured to rotate about a crankshaft axis in response to reciprocation of the piston, and an aluminum crankcase cover including a cover mounting surface. The block mounting surface contacts the cover mounting surface. The block mounting surface and the cover mounting surface are both positioned at an angle to the crankshaft axis and the angle is not 90 degrees.

Technology is provided for a bilateral engine control system for use on a multi-cylinder opposed piston engine. The system includes first and second sets of injectors, each set mountable on first and second sides of an engine. Each injector is in fluid communication with a corresponding cylinder of the engine. First and second engine control units are each connected to a respective set of injectors. First and second crankshaft speed sensors are connected to respective engine control units. The first engine control unit independently controls the first set of injectors based on a first speed signal and the second engine control unit independently controls the second set of injectors based on a second speed signal. The first engine control unit and the second engine control unit are configured to activate corresponding injectors of the first and second sets of injectors at substantially the same time.

A machine includes a prime mover having a power take-off, a chassis configured to support at least an operator and the prime mover, a subframe pivotally coupled to the chassis about a pivot axis at a first location, at least one drive device configured to drive wheels of the machine, a drive belt and pulley arrangement. The subframe is further coupled to the chassis via at least one suspension device at a second location. The at least one drive device is driven by the prime mover and is coupled to the subframe. The pulley arrangement is configured to direct the drive belt from the power take-off of the prime mover to at least one drive pulley on the at least one drive device. The pulley arrangement comprises an idler pulley having a diameter and a rotational axis. The idler pulley is coupled to the chassis such that the rotational axis is spaced from the pivot axis by no greater than 1.5 times the diameter.

An engine includes a crank shaft inside a crankcase and an oil pan and penetrates the crankcase and the oil pan in an up-down direction. An oil pump and an oil strainer are provided inside the oil pan. The oil pump is coaxial with the crank shaft and is driven by the crank shaft. The crank shaft includes a first region and a second region respectively supported pivotably by a plate-shaped support and the crankcase. The support is provided in the crankcase such that both surfaces of the support are covered by the crankcase and the oil pan and allows communication between the crankcase and the oil pan.

An internal combustion engine that includes an oil baffle in the oil sump. The internal combustion engine may include a crankcase comprising an oil sump containing an oil reservoir, a crankshaft, and an oil baffle positioned within the oil sump. The crankshaft may be a vertical crankshaft and a first balance shaft may extend upward from the oil baffle. The crankshaft may be positioned within the oil baffle and a drivetrain may, also optionally, be positioned in the oil baffle. The internal combustion engine may be configured such that the oil reservoir has a first oil level when the internal combustion engine is off and a second oil level when the internal combustion engine is running at normal operating conditions. The first oil level is above a floor of the oil baffle. The second oil level may, also, be above the floor of the oil baffle.

An engine includes an engine housing defining a pair of cylinders, a pair of ignitor cylinders and a crankcase, a pair of cylinder heads connected to the engine housing and enclosing the pair of cylinders, a pair of spark plugs connected to the pair of cylinder heads and in communication with the pair of cylinders, a piston assembly in communication with the pair of cylinders, a rocker arm connected to the piston assembly, a connecting rod connected to the rocker arm, and a drive shaft disposed within the crankcase and connected to the connecting rod, a pair of ignitor cylinder plugs fit within the pair of ignitor cylinders, ignitor piston rod apertures formed though the engine housing, and rod aperture plugs fit within the piston rod apertures.

A variable compression ratio internal combustion engine is provided with a variable compression ratio mechanism in which a mechanical compression ratio of the internal combustion engine changes in accordance with a rotational position of a control shaft, a low compression ratio side stopper, a high compression ratio side stopper, a sensor for detecting a rotational position of a drive shaft of an actuator, and an arm press-fitted onto the drive shaft Relative rotation between the arm and the drive shaft occurs when a torque exceeding an upper-limit torque has been applied, The drive shaft or the control shaft is caused to move to restriction positions restricted by the respective stoppers, and then a diagnosis on the presence or absence of the relative rotation is executed, based on the detected values at the respective restriction positions.

A machine includes a prime mover having a power take-off, a chassis configured to support at least an operator and the prime mover, a subframe pivotally coupled to the chassis about a pivot axis at a first location, at least one drive device configured to drive wheels of the machine, a drive belt and pulley arrangement. The subframe is further coupled to the chassis via at least one suspension device at a second location. The at least one drive device is driven by the prime mover and is coupled to the subframe. The pulley arrangement is configured to direct the drive belt from the power take-off of the prime mover to at least one drive pulley on the at least one drive device. The pulley arrangement comprises an idler pulley having a diameter and a rotational axis. The idler pulley is coupled to the chassis such that the rotational axis is spaced from the pivot axis by no greater than 1.5 times the diameter.

Upper anti-vibration mounts have axial lines arranged in parallel to a longitudinal center line extending in a longitudinal direction of the outboard motor body. Lower anti-vibration mounts have axial lines concentrated on one point on the longitudinal center line extending in a longitudinal direction of the outboard motor body. Meanwhile, the axial lines are inclined at the identical angle symmetrically with respect to the longitudinal center line, so that they intersect in a V-shape in front of the support shaft as seen in a plan view of the outboard motor body.