Fuel supply system and related method for engines

An internal combustion engine comprising:

• an engine body;
• a fuel reservoir;
• a pressure pulse source;
• first and second pressure-operated fuel pumps operably coupled to the pressure pulse source and configured to deliver fuel from the fuel reservoir to a carburetor or a fuel injector;
• the first and second pressure-operated fuel pumps supported directly or indirectly by the engine body;
• the first pressure-operated fuel pump comprising a first fuel chamber, a first pressure chamber, and a first diaphragm separating the first fuel chamber and the first pressure chamber;
• the second pressure-operated fuel pump comprising a second fuel chamber, a second pressure chamber, and a second diaphragm separating the second fuel chamber and the second pressure chamber;
• each of first and second pressure chambers operably coupled to the pressure pulse source;
• and
• each of first and second fuel chambers forming a portion of the primary fuel supply path.

An internal combustion engine comprising:

• a fuel reservoir;
• a crankcase chamber experiencing pressure pulses;
• and
• at least one pressure-operated fuel pump operably coupled to the crankcase chamber by one or more pressure pulse conduits, the one or more pressure pulse conduits sloped so that carryover oil carried into the one or more pressure pulse conduits drains by gravity back into the crankcase chamber.