Vedeneyev M-14P, Maintenance Manual

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is brazed to the other end of the frame. The filter assembly is sealed in the housing with a rubber sealing
ring.
Venturi (14) is inserted into the carburetor barrel from the lower flange side. The nozzle with sleeve are
accommodated in the venturi slot.
2.2.6. Mechanical Acceleration Pump
Piston (6) of the mechanical acceleration pump reciprocates Inside a steel cylinder of valve (9) (Ref. Pig. 2)
pressed in the carburetor body. A wide cylindrical bore in the body near the cylinder communicates with the fuel
chamber of the pressure regulator by a passage drilled in a special boss. Thus, fuel fed from the fuel chamber of
the pressure regulator fills the annular space between the cylinder and the bore wall in the body and gets inside the
cylinder through radial holes drilled in it.
Piston (6) of the mechanical acceleration pump, turned as a hollow thin-walled cylinder, has an internal
partition with four fuel holes iniformly spaced around the circumference. A boss with internal through hole is
provided at the center at one side of the partition. The other side of the partition has a lapped surface.
Two shallow dirt traps are turned on the outer surface of the piston.
Valve (7) being a flat duralumin washer is fitted, with its hole on the cylindrical band at the middle part of
coupling (8). This cylindrical band serves as a valve guide.
Coupling (8) is installed with a small radial clearance in the central through hole of piston (6) to thrust
against the middle bend end.
The coupling is locked against longitudinal play with a lock crimped in the groove on the coupling end
protruding from the piston. Mechanical acceleration pump flat valve (7) moves longitudinally within the guide band
length. In the leftmost position it is tightly pressed by fuel pressure to the lapped surface of the piston partition to
shut off fuel holes; on the other hand when being moved rightward to thrust against the end of the head on the right
end of the coupling, it opens the holes and forms a gap for free passage of fuel.
The coupling flat shank is intended for mating with the slot of adjustment shaft (33). Pressed in the internal
cylindrical bore in the coupling head is a bushing with a central through rectangular hole for passing the flat shank
of the metering needle. The bushing is fixed in the coupling by a round pin pressed in the holes of the coupling and
bushing. Spring (5) constantly presses the mechanical acceleration pump piston assembly to the end face of the
metering needle flat shank. Thus, any longitudinal displacement of the needle causes the same displacement of the
pump piston. The same spring takes up clearance between metering needle trunnion (16) and lever barrel-like roller
(38). The left end of the spring bears against cover (4) of the mechanical acceleration pump. The cover is attached
to the carburetor body by three