PURPOSE: To attempt quickness of readjusting work without cutting a sealing cap when a fuel limiting bolt is readjusted by a maker.

CONSTITUTION: A fuel limiting device for an engine is so constituted that slipping-off of a sealing cap 7 to the back side is prevented by an engaging claw 10 to be engaged with a front surface 11 of an antislipping locking body 6, and at least one of the antislipping locking body 6 and the engaging claw 10 is formed out of a thermoplastic resin, and an electric heating body 14 is interposed between the front surface 11 of the antislipping locking body 6 and the engaging claw 10. Moreover, when electric power is supplied to the electric heating body 14, at least one out of the antislipping locking body 6 and the engaging body 10 is softened or melted by generated heat of this electric heating body 14, thereby the engagement of the engaging claw 10 with the front surface 11 of the antislipping locking body 6 is released.