Abstract: A fuel mixer is provided that delivers a mixture of a gaseous fuel and air to an internal combustion engine by way of multi-stage operation by way of sequentially actuated primary and secondary throttle valves. The fuel mixer may include primary and secondary venturies that are defined within primary and secondary venturi tubes. The secondary venturi tube may be longitudinally aligned with an outlet of the fuel mixer. The primary venturi tube may be arranged at an angle with respect to the secondary venturi tube and the outlet of the fuel mixer.

Abstract: A method is provided for exercising an engine-driven, electrical generator. The generator has a first operation mode wherein the generator generates a predetermined output voltage at a predetermined frequency with the engine running a predetermined operating speed and a second exercise mode. The method includes the step of running the engine at a predetermined exercise speed with the generator in the exercise mode. The predetermined exercise speed is in the range of 40% to 70% of the predetermined operating speed of the engine. In addition, in the exercise mode, the generator generates an exercise voltage that is less than the predetermined output voltage.

Abstract: A method is provided for cooling an engine driven, electrical generator set and for reducing the fan noise associated with operation of the same. The method includes positioning a fan on the first side of the radiator. The temperature adjacent a first side of the radiator is monitored and the fan is rotated in response to the temperature of the air on the first side of the radiator exceeding a threshold. The fan urges air through the radiator in order to cool the engine coolant flowing therethrough.

Abstract: An apparatus has first and second driven pulleys for powering an engine auxiliary function, e.g., a water pump, and for driving an engine fan, respectively. The apparatus includes a hollow tube-like arbor fixed with respect to the first pulley and having a first arbor surface, e.g., an exterior cylindrical surface. A bearing has a first load-supporting surface, e.g., the interior surface of the bearing, which is mounted to the first arbor surface. A fan drive member is mounted to the second load-supporting surface of the bearing, e.g., the exterior bearing surface, and both the fan and the second pulley are coupled to the fan drive member. The two pulleys are driven by respective belts powered by the engine crankshaft and the pulleys rotate in opposite directions when driven. A new engine incorporating the apparatus is also disclosed.