To suppress the variation in the amount of delivery of acceleration fuel by improving accuracy of a plunger stroke in a carburetor with an acceleration pump.

The carburetor 1A with the acceleration pump includes: an acceleration pump mechanism having a cylinder 10 for introducing the fuel; a rod 14A reciprocated in an axial direction through a link system interlocking with opening and closing operation of a throttle valve while inserting a distal end side to the cylinder 10; a plunger 16 lowered by the distal end of the rod 14A pushing a rod abutment face 16a on a base end side and raised by repulsion force of a return spring 17, and reciprocated in the cylinder 10; a guide member 15A arranged above the plunger 16 and guiding the stroke of the rod 14A; and an acceleration fuel passage 18 for delivering the fuel compressed by the plunger 16 to an intake passage 2 side. An operational error of the link system is absorbed by a gap (w) having a predetermined width which is generated between the distal end of the rod 14A and the rod abutment face 16a at the position of a top dead center of the plunger 16.