ARRANGEMENT STRUCTURE FOR FUEL INJECTION DEVICE OF MOTORCYCLE

A motorcycle (1) includes: a vehicle body frame (2) having a main frame (12) as a back bone formed of a linear first half portion (51) inclined downward and backward， an arcshaped intermediate portion (52) connected to a rear end of the first half portion (51)， and a linear second half portion connected to a rear end of the intermediate portion (52) and inclined downward and backward more gently than the first half portion (51); a steering mechanism (6) located in front of the main frame (12) and rotatably supporting a front wheel (5); a swing arm (8) supporting a rear wheel (7) located in a rear of the main frame (12) swingably in the vertical direction; an air cleaner (42) located under the first half portion of the main frame (12); an engine (9) located below the main frame (12) and on a rear side of the air cleaner (42) and including a cylinder head (26) having an intake port (43)， the cylinder head (26) being directed forward and the engine (9) having a substantially horizontal cylinder center line; an intake passage (45) extending backward in a manner inclined downward from the air cleaner (42) and connected to the intake port (43) of the engine (9); a throttle valve (46) provided in the intake passage (45) for adjusting an intake flow rate; a fuel injection device (47) located on a downstream side of the throttle valve (46) and below the second half portion of the main frame (12); a bypass passage connecting an upstream side and the downstream side of the throttle valve (46); and an idle speed control valve (49) located above the throttle valve (46) and between the air cleaner (42) and the fuel injection device (47) for adjusting an intake flow rate of the bypass passage.