Four-cycle engine lubrication structure

A four-cycle engine having a lubricating structure for lubricating said engine and a transmission with a common lubricating oil, comprising:

• a crank chamber;
• an oil sump for lubricating oil provided at a lower part of the crank chamber of the four-cycle engine;
• a reed valve provided at an outlet of the oil sump, said reed valve being openable when pressure in the crank chamber is high;
• and
• an oil passage sloping upwards from the outlet of the oil sump, an outlet of the oil passage being provided above a surface level of oil accumulated within a bottom part of a transmission chamber of the transmission.

A four-cycle engine having a transmission which is lubricated with a common lubricating oil, comprising:

• a pair of crankcases, said pair of crankcases being partitioned into a crank chamber and a transmission chamber;
• an oil sump for the common lubricating oil provided at a lower part of said crank chamber;
• a reed valve provided at an outlet of the oil sump, said reed valve being openable when pressure in the crank chamber is high;
• and
• an oil passage sloping upwards from the outlet of the oil sump, an outlet of the oil passage being provided above a surface level of oil accumulated in a bottom part of the transmission chamber.