Engine and straddle type vehicle

摘要

An engine of the invention includes a crankcase (20), which is configured to be dividable by a dividing surface (S1) intersecting an axial center of a crankshaft (40) and an axial center of a balancer shaft (47b). When the engine is mounted on a vehicle, the axial center of the balancer shaft (47b) is disposed between a first horizontal surface (S13) intersecting the axial center of the crankshaft (40) and a second horizontal surface (S12) intersecting a lower end of a crank web.