Exhaust system of engine of motorcycle

An exhaust system of an engine of a motorcycle, the engine being an in-line four-cylinder engine, comprising:

• an exhaust pine configured to extend in one of an upward direction and a downward direction from four exhaust ports arrange in a width direction of the engine at a front portion of the engine and to then be bent to extend in and opposite direction to form a bent portion at a location in front of the engine;
• wherein the bent portion includes a lower bent portion and an upper bent portion located above the lower bent portion, the exhaust pipe extending in the downward direction and then being bent to extend in the upward direction to form the lower bent portion, the exhaust pip extending in the upward direction and then being bent to extend in the downward direction to form the upper bent portion;
• wherein the exhaust pipe is configured to extend downward from the exhaust ports. upward from the lower bent portion, downward from the upper bent portion and then rearward;
• wherein the exhaust pipe includes a right upstream pipe through which exhaust gases from two exhaust ports located on a right side of the vehicle body as viewed from above are guided and gathered, a left upstream pipe through which exhaust gases from two exhaust ports located on a left side of the vehicle body as viewed from above are guided and gathered, an intermediate pipe through which exhaust gases from the right upstream pipe and the left upstream pipe are guided and gathered, and a downstream pipe through which an exhaust gas from the intermediate pipe Is guided outside the engine;
• wherein each of the right upstream pipe and the left upstream pipe has the lower bent portion and is coupled to the intermediate pipe at a location downstream of the lower bent portion;
• and wherein the intermediate pipe has the upper bent portion and is coupled to the downstream pipe at a location downstream of the upper bent portion.

An exhaust system of an engine of a motorcycle, the engine being an In-line tour-cylinder engine, comprising:

• an exhaust pipe configured to extend in one of an upward direction and a downward direction from four exhaust ports arranged in a width direction of the engine at a front portion of the engine and to then be bent to extend in an opposite direction to form a bent portion at a location in front of the engine,
• wherein the bent portion includes a lower bent portion and an upper bent portion located above the lower bent portion, the exhaust pipe extending in the downward direction and then being bent to extend in the upward direction to form the lower bent portion, the exhaust pipe extending in the upward direction and then being bent to extend in the downward direction to form the upper bent portion;
• wherein the exhaust pipe is configured to extend downward from the exhaust ports, upward from the lower bent portion, downward from the upper bent portion and then rearward;
• wherein the exhaust pipe includes a right upstream pipe through which exhaust gases from two exhaust ports located on a right side of the vehicle body as viewed from above are guided and gathered, a left upstream pipe through which exhaust gases from two exhaust ports located on a left side of the vehicle body are guided and gathered, a right downstream pipe through which the exhaust gas from the right upstream pipe flows, and a left downstream pipe through which the exhaust gas from the left upstream pipe flows;
• wherein each of the right upstream pipe and the left upstream pipe has the lower bent portion, and the right upstream pipe and the left upstream pipe are coupled to the right downstream pipe and the left downstream pipe, respectively, at a location downstream of the lower bent portion;
• and wherein each of the right downstream pipe and the left downstream pipe has the upper bent portion, and the right downstream pipe and the left downstream pipe are coupled to right and left mufflers, respectively, at a location downstream of the upper bent portion.