An air cleaner device 41 which includes a main air cleaner 56 and
a sub air cleaner 67 which is connected to the main air cleaner 56,
and the sub air cleaner 67 is arranged parallel to the main air cleaner
56 in the longitudinal direction of main frames 55. In this arrangement,
the air cleaner device does not projected sideward from a vehicle body and hence,
the interference of the air cleaner device with an occupant and lowering of aesthetic
appearance of a vehicle can be prevented. Further, since there is no restriction
imposed by the interference of the air cleaner device with an occupant and lowering
of aesthetic appearance of the vehicle, a capacity of air cleaner device can be
easily ensured.