Misfire detection device and vehicle

A misfire detection device for detecting a misfire in a four-stroke engine that drives a wrapping transmission element wrapped around a plurality of transmission wheels so as to move circularly, the misfire detection device comprising a processor configured to execute a control program to implement:

• a rotation speed acquisition unit configured to acquire a rotation speed of a rotator rotated by the four-stroke engine;
• a misfire determination unit configured to determine a presence or absence of a misfire in the four-stroke engine based on the rotation speed of the rotator acquired by the rotation speed acquisition unit;
• and
• a periodic fluctuation detection unit configured to detect a periodic fluctuation contained in a rotation fluctuation of the four-stroke engine based on a rotation speed acquired by the rotation speed acquisition unit, the periodic fluctuation being repeated on a circulation cycle of at least one element of the wrapping transmission element or the plurality of transmission wheels, the periodic fluctuation having a plurality of extreme values within the circulation cycle of the one element.