Abstract: A valve system is disclosed herein. The valve system, in one arrangement, may comprise: a fluid pathway for transporting a fluid; a first valve operably coupled to the fluid pathway, the first valve comprising a first resilient element; a second valve operably coupled to the fluid pathway, the second valve comprising a second resilient element that is substantially identical to the first resilient element; wherein, when the first valve is in a closed state, the first resilient element is compressed to a first length so that the first valve opens at a first pressure; and wherein, when the second salve is in a closed state, the second resilient element is compressed to a second length so that the second valve opens at a second pressure, the first length is less than the second length such that the second pressure is less than the first pressure.

Abstract: A valve system is disclosed herein. The valve system, in one arrangement, may comprise: a fluid pathway for transporting a fluid; a first valve operably coupled to the fluid pathway, the first valve comprising a first resilient element; a second valve operably coupled to the fluid pathway, the second valve comprising a second resilient element that is substantially identical to the first resilient element; wherein, when the first valve is in a closed state, the first resilient element is compressed to a first length so that the first valve opens at a first pressure; and wherein, when the second salve is in a closed state, the second resilient element is compressed to a second length so that the second valve opens at a second pressure, the first length is less than the second length such that the second pressure is less than the first pressure.

Abstract: A lubrication system for an internal combustion engine. The lubrication system may comprise an oil cooler; an oil cooler supply passage for delivering oil to an inlet of the oil cooler from an oil reservoir; an oil cooler outlet passage for delivering oil from an outlet of the oil cooler to one or more portions of the internal combustion engine to be lubricated; a first pressure relief valve operably coupled to the oil cooler supply passage, the first pressure relief valve configured to open at a first predetermined pressure to allow oil in the oil cooler supply passage to return to the oil reservoir without passing through the oil cooler; and a second pressure relief valve operably coupled to the oil cooler outlet passage, the second pressure relief valve configured to open at a second predetermined pressure to allow oil in the oil cooler outlet passage to return to the oil reservoir after passing through the oil cooler, the second predetermined pressure being less than the first predetermined pressure.

Abstract: A lubrication system for an internal combustion engine. The lubrication system may comprise an oil cooler; an oil cooler supply passage for delivering oil to an inlet of the oil cooler from an oil reservoir; an oil cooler outlet passage for delivering oil from an outlet of the oil cooler to one or more portions of the internal combustion engine to be lubricated; a first pressure relief valve operably coupled to the oil cooler supply passage, the first pressure relief valve configured to open at a first predetermined pressure to allow oil in the oil cooler supply passage to return to the oil reservoir without passing through the oil cooler; and a second pressure relief valve operably coupled to the oil cooler outlet passage, the second pressure relief valve configured to open at a second predetermined pressure to allow oil in the oil cooler outlet passage to return to the oil reservoir after passing through the oil cooler, the second predetermined pressure being less than the first predetermined pressure.

Abstract: A venturi insert for a carburetor, and a carburetor, system and apparatus incorporating the same. In one embodiment, the invention is a carburetor for an internal combustion engine comprising: a carburetor body comprising a plurality of throttle bores extending through the carburetor body, and for each of the throttle bores a fuel delivery passage terminating at a sidewall of the throttle bore; an insert comprising a plurality of venturi tubes and a linking member connecting the venturi tubes together, each of the venturi tubes comprising a venturi passage and a fuel port for introducing fuel into the venturi passage; and the insert secured to the carburetor body so that the venturi tubes extend into the throttle bores and the fuel ports are in fluid communication with the fuel delivery passages, and the linking member is in contact with the carburetor body.

Abstract: In at least some embodiments, the present invention relates to an air cleaner having a housing portion, and a low profile rain cover having an opening on an underside of the cover to allow unfiltered air to enter into the air cleaner. Also, in at least some embodiments, the present invention relates to an air cleaner including a housing and an additional component by which the air cleaner is capable of being directly coupled to a carburetor inlet. In some such embodiments, one or more protrusions can be provided within a channel formed by the housing/additional component to influence air flow. Further, in at least some embodiments, the present invention relates to an air cleaner having a shaped wall formed on a housing portion, where the shaped wall includes both an interior surface and an exterior surface by which air flowing within the air cleaner is imparted with helical motion.

Abstract: A venturi insert for a carburetor, and a carburetor, system and apparatus incorporating the same. In one embodiment, the invention is a carburetor for an internal combustion engine comprising: a carburetor body comprising a plurality of throttle bores extending through the carburetor body, and for each of the throttle bores a fuel delivery passage terminating at a sidewall of the throttle bore; an insert comprising a plurality of venturi tubes and a linking member connecting the venturi tubes together, each of the venturi tubes comprising a venturi passage and a fuel port for introducing fuel into the venturi passage; and the insert secured to the carburetor body so that the venturi tubes extend into the throttle bores and the fuel ports are in fluid communication with the fuel delivery passages, and the linking member is in contact with the carburetor body.

Abstract: In at least some embodiments, the present invention relates to an air cleaner having a housing portion, and a low profile rain cover having an opening on an underside of the cover to allow unfiltered air to enter into the air cleaner. Also, in at least some embodiments, the present invention relates to an air cleaner including a housing and an additional component by which the air cleaner is capable of being directly coupled to a carburetor inlet. In some such embodiments, one or more protrusions can be provided within a channel formed by the housing/additional component to influence air flow. Further, in at least some embodiments, the present invention relates to an air cleaner having a shaped wall formed on a housing portion, where the shaped wall includes both an interior surface and an exterior surface by which air flowing within the air cleaner is imparted with helical motion.

Abstract: In at least some embodiments, the present invention relates to an air cleaner having a housing portion, and a low profile rain cover having an opening on an underside of the cover to allow unfiltered air to enter into the air cleaner. Also, in at least some embodiments, the present invention relates to an air cleaner including a housing and an additional component by which the air cleaner is capable of being directly coupled to a carburetor inlet. In some such embodiments, one or more protrusions can be provided within a channel formed by the housing/additional component to influence air flow. Further, in at least some embodiments, the present invention relates to an air cleaner having a shaped wall formed on a housing portion, where the shaped wall includes both an interior surface and an exterior surface by which air flowing within the air cleaner is imparted with helical motion.

Abstract: In at least some embodiments, the present invention relates to an air cleaner having a housing portion, and a low profile rain cover having an opening on an underside of the cover to allow unfiltered air to enter into the air cleaner. Also, in at least some embodiments, the present invention relates to an air cleaner including a housing and an additional component by which the air cleaner is capable of being directly coupled to a carburetor inlet. In some such embodiments, one or more protrusions can be provided within a channel formed by the housing/additional component to influence air flow. Further, in at least some embodiments, the present invention relates to an air cleaner having a shaped wall formed on a housing portion, where the shaped wall includes both an interior surface and an exterior surface by which air flowing within the air cleaner is imparted with helical motion.

Abstract: An engine having an oil circuit and method of communicating oil within an engine are disclosed. The engine includes a crankcase, a pump, and a camshaft having a first channel extending between first and second ends of the camshaft, where lubricant is provided from the pump to the first channel at the first end and communicated by way of the first channel to the second end. The engine also includes a crankshaft, a second channel communicating at least some of the lubricant delivered to the second end of the first camshaft to a crankshaft bearing, and a third channel within the crankshaft that receives at least some of the lubricant communicated by the second channel and communicates at least some of the lubricant to a crankpin bearing on the crankshaft. In some embodiments, lubricant is communicated by the third channel to an eccentric bearing configured to support a balance weight.

Abstract: A crankcase, and method of assembling a crankcase, of an internal combustion engine are disclosed. The crankcase includes a top including at least a first portion of a top surface of the crankcase, and a bottom including a bottom surface of the crankcase and a plurality of side surfaces of the crankcase. The side surfaces are substantially vertical and extend between the top and bottom surfaces. The crankcase further includes bearings within at least one of the top and bottom to support a crankshaft. The crankcase additionally includes a first interface at which at least one of the top, bottom and side surfaces is coupled to a cylinder. The bottom and top interface one another along a split line, the top is removable from the bottom, and the top is configured to be attached to at least one of an oil filter component, a starter, and an ignition module.

Abstract: A cover for a crankcase of an internal combustion engine is disclosed. The cover has an inside surface in which walls are formed extending from the inside surface to form channels. A plate covers the channels to form passages that allow the flow of oil from various inlets to various outlets in the passages, but does not necessarily completely seal the channels. The plate is secured to the inside surface of the cover by threaded members that are inserted through fastening apertures in the plate and are threaded into corresponding internally threaded apertures in the inside surface of the cover.

Abstract: An engine having an oil circuit and method of communicating oil within an engine are disclosed. The engine includes a crankcase, a pump, and a camshaft having a first channel extending between first and second ends of the camshaft, where lubricant is provided from the pump to the first channel at the first end and communicated by way of the first channel to the second end. The engine also includes a crankshaft, a second channel communicating at least some of the lubricant delivered to the second end of the first camshaft to a crankshaft bearing, and a third channel within the crankshaft that receives at least some of the lubricant communicated by the second channel and communicates at least some of the lubricant to a crankpin bearing on the crankshaft. In some embodiments, lubricant is communicated by the third channel to an eccentric bearing configured to support a balance weight.

Abstract: An air filter and corresponding filter element for use in an internal combustion engine are disclosed. The filter element has a seal bead made of an elastomeric material that forms the frame of the filter element. A pleat block, made of a filter media, is molded into the seal bead in a first area of the filter element and a baffle is located in a second area of the filter element to protect the pleat block from wetting. A channel is formed in one side of the seal bead which allows the filter element to be retained during assembly without the use of fasteners and a surface is formed opposite the seal bead that in conjunction with the channel seals the filter element within the air filter when the air filter is fully assembled. The air filter has an intake silencing chamber that is located to receive outside air before it is provided to the pleat block and a sealed flow path is created from the intake silencing chamber to the pleat block by a third area of the filter element.

Abstract: A cylinder head assembly and a method of providing an air-fuel mixture from a carburetor to a cylinder of an internal combustion engine are disclosed. The cylinder head assembly includes a cylinder head and a component coupled to the cylinder head. The cylinder head includes a first port having a first passage linking a first end to an intersection, and a second passage linking a second end to the intersection, where the intersection includes an abrupt transition between the first and second passages. The component includes a tongue that protrudes into the first passage from the first end to proximate the intersection, where the tongue is positioned along at least a portion of an inner side of the first passage, and where the tongue is gradually-reduced in thickness at least proximate the intersection.

Abstract: An internal combustion engine, and method of distributing lubricant within an internal combustion engine, are disclosed. The internal combustion engine includes a crankcase having a floor, a pump supported by the floor, and a camshaft. The pump includes an inlet and an outlet. The camshaft has a cam, first and second camshaft ends, and an internal channel extending within the camshaft between the ends. The first end is supported by the pump or the floor. Rotation of the camshaft causes the pump to draw in lubricant via the inlet and to pump out at least some of the lubricant via the outlet. The outlet is positioned in proximity to the internal channel at the first camshaft end, so that at least some of the lubricant is pumped into the channel.

Abstract: A cylinder head assembly and a method of providing an air-fuel mixture from a carburetor to a cylinder of an internal combustion engine are disclosed. The cylinder head assembly includes a cylinder head and a component coupled to the cylinder head. The cylinder head includes a first port having a first passage linking a first end to an intersection, and a second passage linking a second end to the intersection, where the intersection includes an abrupt transition between the first and second passages. The component includes a tongue that protrudes into the first passage from the first end to proximate the intersection, where the tongue is positioned along at least a portion of an inner side of the first passage, and where the tongue is gradually-reduced in thickness at least proximate the intersection.

Abstract: An air filter and corresponding filter element for use in an internal combustion engine are disclosed. The filter element has a seal bead made of an elastomeric material that forms the frame of the filter element. A pleat block, made of a filter media, is molded into the seal bead in a first area of the filter element and a baffle is located in a second area of the filter element to protect the pleat block from wetting. A channel is formed in one side of the seal bead which allows the filter element to be retained during assembly without the use of fasteners and a surface is formed opposite the seal bead that in conjunction with the channel seals the filter element within the air filter when the air filter is fully assembled. The air filter has an intake silencing chamber that is located to receive outside air before it is provided to the pleat block and a sealed flow path is created from the intake silencing chamber to the pleat block by a third area of the filter element.