Engine valve train device

An engine valve train device in which an intermediate driven wheel disposed in the vicinity of a camshaft is driven by a crankshaft-side driving wheel formed on a crankshaft and a camshaft gear fixed to the camshaft is driven by an intermediate gear disposed on a support shaft on which the intermediate driven wheel is disposed, the intermediate gear integrally rotating with the intermediate driven wheel, the engine valve train device being characterized in that a reduction ratio from the crankshaft-side driving wheel to the intermediate driven wheel is set larger than a reduction ratio from the intermediate gear to the camshaft gear, in that the intermediate gear is made smaller in diameter than the intermediate driven wheel to such an extent that a pitch circle of the intermediate gear passes substantially an intermediate between a diameter of a boss and a pitch circle of the intermediate driven wheel and the intermediate gear is disposed on a back side of the intermediate driven wheel, in that an inspection hole is formed in the intermediate driven wheel for visualizing a meshing portion where the intermediate gear and the camshaft gear mesh with each other, and in that an alignment mark is formed on a tooth portion of the intermediate gear and the camshaft gear, respectively.