Two-cycle combustion engine having two-staged piston

A two-cycle combustion engine comprising:

• a cylinder block having a cylinder bore;
• a piston drivingly mounted in the cylinder bore;
• a crankcase mounted on the cylinder block;
• a crankshaft coupled with the piston and rotatably mounted in the crankcase;
• an air passageway for introducing air into the crankcase;
• a carburetor operatively enabling an air-fuel mixture to be supplied to the cylinder bore, through an injection passageway;
• and
• an insulator assembly mounting the carburetor on the cylinder block, the insulator assembly having a plurality of valves including a first valve for selectively opening/closing the air passageway, and a second valve for selectively opening/closing the injection passageway, wherein the insulator assembly is made of a synthetic resin and .the first and second valves are check valves.

A two-cycle combustion engine comprising:

• a cylinder block having a cylinder bore;
• a piston drivingly mounted in the cylinder bore;
• a crankcase mounted on the cylinder block;
• a crankshaft coupled with the piston and rotatably mounted in the crankcase;
• an air passageway for introducing air into the crankcase;
• a carburetor operatively enabling an air-fuel mixture to be supplied to the cylinder bore, through an injection passageway;
• and
• an insulator assembly mounting the carburetor on the cylinder block, the insulator assembly having a plurality of valves including a first valve for selectively opening/closing the air passageway, and a second valve for selectively opening/closing the injection passageway,
• wherein the insulator assembly includes the injection passageway and a third valve for selectively opening/closing the injection passageway.

A two-cycle combustion engine which comprises:

• a cylinder block having a two-staged cylinder bore defined therein, said two-staged cylinder bore having a reduced diameter bore portion and a large diameter bore portion;
• a two-staged piston having a reduced diameter piston portion and a large diameter piston portion and drivingly accommodated within the two-staged cylinder bore;
• an annular auxiliary chamber defined between the large diameter bore portion of the two-staged cylinder bore and the reduced diameter piston portion of the two-staged piston;
• an air passage for introducing air into a crank chamber;
• an air-fuel mixture passage for introducing the air-fuel mixture into the auxiliary chamber;
• a scavenge air passage for supplying the air within the crank chamber into a combustion chamber;
• an injection passage for injecting the air-fuel mixture within the auxiliary chamber into the combustion chamber from an inner peripheral surface of the cylinder block in a direction oriented substantially diagonally upwardly;
• a first check valve for selectively openingor closing the air passage;
• a second check valve for selectively opening or closing the air-fuel mixture passage;
• a third check valve for selectively opening or closing the injection passage;
• and
• a carburetor for preparing the air-fuel mixture by mixing air, supplied through an air cleaner, with fuel, said carburetor having a portion of the air passage in addition to a portion of the air-fuel mixture passage, and a single valve for adjusting an opening of each of the air-fuel mixture passage and air passage.