To provide a drive structure for a fuel injection pump designed for reducing a bending moment for a crankshaft operated by a tension of a drive belt.

In an engine 14 provided with a flywheel magneto device 34 at an end part of a crankshaft 20 and the fuel injection pump 57, the flywheel magneto device 34 annexing a starter pulley 40 of a recoil starter 39 for starting the engine, a pump drive pulley 38 for delivering rotation of the crankshaft 20 to the fuel injection pump 57 through a pump drive belt 63 is disposed adjacent to a flywheel 37 of the flywheel magneto device 34 fixed to the end part of the crankshaft 20 through a boss 36. The starter pulley 40 is disposed adjacent to the pump drive pulley 38, and the flywheel 37, the pump drive pulley 38 and the starter pulley 40 are fastened together at the end part of the crankshaft 20 by a bolt 41.