US Patent 7556019 Intake manifold regulators for internal combustion engines

The present invention provides an internal combustion engine including an engine housing, a crankshaft rotatably supported in the engine housing, a cylinder, a piston movable within the cylinder, a combustion chamber in fluid communication with the cylinder, a fuel system configured to provide fuel to the combustion chamber, an intake passageway configured to provide a fluid to the combustion chamber, and a first regulator at least partially positioned in the intake passageway. The first regulator is selectable from a plurality of regulators. The engine also includes a coupling device configured to maintain the first regulator in the intake passageway. The first regulator is configured to be removed and replaced by a second regulator from the plurality of regulators without disassembly of the intake passageway.