Limiting cap

A limiting cap assembled onto a needle valve which is screwed into an adjustment hole of a fuel adjuster, comprising:

• a main body in a cylindrical shape to be arranged onto a protruding part of the needle valve which protrudes from the adjustment hole,
• wherein a rising part, which is inserted into a recess formed in the fuel adjuster for restricting rotation of the needle valve, is formed on an outer peripheral surface of the main body,
• the main body includes an engagement part on a side closer to the adjustment hole and a fixing part on a side away from the adjustment hole with respect to the engagement part,
• a first splined part formed in an inner peripheral surface of the engagement part is engageable in a circumferential direction of the main body with a second splined part formed in an outer peripheral surface of the needle valve,
• a needle valve fixed part of the needle valve is press-fitted into the fixing part, at a position away from the adjustment hole with respect to the engagement part,
• the fixing part is formed to have a smaller inner diameter than the engagement part, and
• a space, extending from the fixing part to an end surface of the main body away from the adjustment hole, defined in a radial direction between a groove within which a tool is to be inserted and the main body, and including a larger inner radial diameter than any point along an inner surface of the fixing part, the space creating a gap between the needle valve and the limiting cap.