Engine starting apparatus for an all-terrain vehicle

An engine, comprising:

• a crankshaft;
• a transmission;
• a gear position sensor for detecting a gear position of the transmission;
• a centrifugal clutch, comprising:
• an inner clutch member which is attached to the crankshaft for concurrent rotation therewith, and
• an outer clutch drum which is operatively connected to the transmission, the centrifugal clutch being capable of engaging when the rotary speed of the crankshaft reaches a predetermined threshold value, wherein the centrifugal clutch operatively connects the crankshaft to the transmission when engaged, to transmit a rotary force of the crankshaft to the transmission;
• wherein the centrifugal clutch is disengaged when the crankshaft turns at a speed below the predetermined threshold value;
• a starter operatively connected to the crankshaft;
• and
• a controller which is operable to enable starting of the engine, according to a start command operation, when the centrifugal clutch is disengaged and when the sensed gear position is a gear position other than reverse;
• whereby, when the engine is started with the transmission engaged in a forward gear, the initial rotary speed of the crankshaft will be below the threshold value, resulting in the centrifugal clutch being disengaged.

An all-terrain vehicle, comprising:

• a frame;
• an engine supported on the frame and comprising a crankshaft and a transmission;
• an ignition switch operatively connected to the engine, such that the engine is capable of being started in response to operation of the ignition switch,
• a starter apparatus comprising:
• a centrifugal clutch for transmitting a rotary force of the crankshaft to the transmission when the rotary speed of the crankshaft reaches a predetermined threshold value;
• a gear position sensor for detecting a gear position of the transmission;
• a starter operatively connected to the cranikshaft;
• and
• a controller which enables starting of the engine according to a start command operation when the crankshaft and the transmission are disconnected by the centrifugal clutch and when the gear position is at one of a neutral position and a forward gear position based on the gear position detected by the gear position sensor
• wherein the centrifugal clutch comprises:
• an inner clutch member which is attached to the crankshaft for concurrent rotation therewith, and
• an outer clutch drum which is operatively connected to the transmission,
• wherein the centrifugal clutch is disengaged when the crankshaft turns at a speed below the predetermined threshold value;
• whereby, when the engine is startfed with the transmission engaged in a forward gear, the initial rotary speed of the crankshaft will be below the threshold value, resulting in the centrifugal clutch being disengaged.

A method of starting an engine of an all-terrain vehicle with a transmission thereof engaged in a forward gear, comprising the steps of:

• operatively rotating a crankshaft of the all-terrain vehicle by rotating a pinion gear of a staffer, where the pinion gear is operatively connected to the crankshaft;
• providing a timed spark to the engine at a time when a piston of the engine has compressed a fuel-air mixture in a combustion chamber thereof;
• wherein the crankshaft is operatively disengaged from the transmission during the staffing of the engine by a centrifugal clutch disposed therebetween, wherein the centrifugal clutch comprises:
• an inner clutch member which is attached to the crankshaft for concurrent rotation therewith, and
• an outer clutch drum which is operatively connected to the transmission,
• wherein the centrifugal clutch is disengaged when the crankshaft turns at a speed below a predetermined threshold value;
• whereby, when the engine is started with the transmission engaged in a forward gear, the initial rotary speed of the crankshaft will be below the threshold value, resulting in the centrifugal clutch being disengaged.