| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotary throttle valve type carburetor to prevent a returning failure of a starting shaft which is operated at starting of a machine. SOLUTION: This throttle valve 1 having a throttle hole 2 is turnably and liftably inserted into a cylindrical valve chamber 6 across an intake passage. A throttle valve lever 22 is connected with an upper edge penetrating a cover plate 21 for closing the valve chamber 6, the upper edge being a valve shaft 1a of the throttle valve 1. A cam mechanism composed of a cam groove of a lower surface of a throttle valve lever 22 and a follower of the cover plate 21 raises a needle 3 together with the throttle valve 1 so as to increase open degree of a fuel injection hole 4a of a fuel supply pipe 4. When the starting shaft 32 supported at a boss part integrated with the cover plate 21 rotates, the throttle valve lever 22 is pushed up by a cam surface 52a of a edge part of a starting shaft 32. A through-hole 54 is provided adjacent to a contact between the starting shaft 32 and the cover plate 21.
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