A power unit (10, 50) to be mounted in a straddled vehicle, comprising: a drive source configured to generate a driving force; a driving wheel driven by the driving force from the drive source; a transmission provided between the drive source and the driving wheel and configured to change a gear ratio; a centrifugal clutch comprising: a centrifugal clutch upstream member that is mechanically connected with the drive source to be rotated; and a centrifugal clutch downstream member that is connected to or disconnected from the centrifugal clutch upstream member by a centrifugal force generated by the rotation of the centrifugal clutch upstream member, wherein the centrifugal clutch is configured to make or cut off transmission of a torque between a centrifugal clutch upstream path and a centrifugal clutch downstream path, by the centrifugal force generated by the rotation of the centrifugal clutch upstream member, the centrifugal clutch upstream path is defined as a path from the drive source to the centrifugal clutch upstream member, and the centrifugal clutch downstream path is defined as a path from the centrifugal clutch downstream member to the driving wheel; a centrifugal clutch upstream rotation detection sensor configured to detect a rotation speed of the centrifugal clutch upstream path; characterized by a centrifugal clutch characteristics storage module configured to store centrifugal clutch characteristics indicating a relationship between rotation speeds of the centrifugal clutch upstream path and clutch torque capacities of the centrifugal clutch in a half-engaged state, wherein, in the half-engaged state, a torque is transmitted between the centrifugal clutch upstream member and the centrifugal clutch downstream member by the centrifugal clutch upstream member sliding relative to the centrifugal clutch downstream member; a centrifugal clutch characteristics estimation module configured to estimate the centrifugal clutch characteristics based on a rotation speed of the centrifugal clutch upstream path; a centrifugal clutch characteristics updating module configured to update the centrifugal clutch characteristics stored in the centrifugal clutch characteristics storage module to the centrifugal clutch characteristics that are estimated by the centrifugal clutch characteristics estimation module; and a driving force control module configured to control a driving force of the driving wheel based on the centrifugal clutch characteristics that are read out from the centrifugal clutch characteristics storage module. a drive source configured to generate a driving force; a driving wheel driven by the driving force from the drive source; a transmission provided between the drive source and the driving wheel and configured to change a gear ratio; a centrifugal clutch comprising: a centrifugal clutch upstream member that is mechanically connected with the drive source to be rotated; and a centrifugal clutch downstream member that is connected to or disconnected from the centrifugal clutch upstream member by a centrifugal force generated by the rotation of the centrifugal clutch upstream member, wherein the centrifugal clutch is configured to make or cut off transmission of a torque between a centrifugal clutch upstream path and a centrifugal clutch downstream path, by the centrifugal force generated by the rotation of the centrifugal clutch upstream member, the centrifugal clutch upstream path is defined as a path from the drive source to the centrifugal clutch upstream member, and the centrifugal clutch downstream path is defined as a path from the centrifugal clutch downstream member to the driving wheel; a centrifugal clutch upstream rotation detection sensor configured to detect a rotation speed of the centrifugal clutch upstream path; characterized by a centrifugal clutch characteristics storage module configured to store centrifugal clutch characteristics indicating a relationship between rotation speeds of the centrifugal clutch upstream path and clutch torque capacities of the centrifugal clutch in a half-engaged state, wherein, in the half-engaged state, a torque is transmitted between the centrifugal clutch upstream member and the centrifugal clutch downstream member by the centrifugal clutch upstream member sliding relative to the centrifugal clutch downstream member; a centrifugal clutch characteristics estimation module configured to estimate the centrifugal clutch characteristics based on a rotation speed of the centrifugal clutch upstream path; a centrifugal clutch characteristics updating module configured to update the centrifugal clutch characteristics stored in the centrifugal clutch characteristics storage module to the centrifugal clutch characteristics that are estimated by the centrifugal clutch characteristics estimation module; and a driving force control module configured to control a driving force of the driving wheel based on the centrifugal clutch characteristics that are read out from the centrifugal clutch characteristics storage module.