Tecumseh ECV105 Technician's Handbook page 26

High and Low Speed Adjusting Screw, Main Nozzle
When reassembling, position the coil spring on the adjusting
screws, followed by the small brass washer and the "O"
ring seal. Turn the high speed adjustment screw in
approximately one turn into the bowl retainer nut to make
an assembly (diag. 47).
On 2-7 hp. engines that use carburetors which have the
metering rod in the idle circuit (carburetor should rattle when
shaking), make certain that the idle adjustment screw is
installed when the carburetor is in an upright position or
the needle will damage the metering rod, adjustment screw
and carburetor casting.
Some carburetors are of the fixed main type and would
not have a high speed adjusting screw.
Inlet Needle and Seat
On float type carburetors, make sure the seat cavity is
clean. Moisten the seat with oil and insert the seat with
the grooved side down and away from the inlet needle.
Press the seat into the cavity using a flat punch close to
the diameter of the seat, making sure it is firmly seated
(diag. 48).
The inlet needle hooks onto the float tab by means of a
spring clip. To prevent binding, the long, straight end of the
clip should face the air intake end of the carburetor as
shown (diag. 49).
On diaphragm carburetors the inlet needle and seat
assembly are installed by using a socket to tighten the
assembly until seated.
Needle and Seat Pop-Off Test
To test the pop-off pressure, remove the carburetor from
the engine. Be sure to drain any fuel into an approved
container. Invert the carburetor and remove the float bowl.
Place a drop of an oil based product such as WD-40 on
the tip of the needle valve. Using a commercially available
0-30 psi pump and gauge, attach the pumps hose to the
carburetor inlet. Apply approximately 6 psi or until the
needle pops off the seat. The needle should seat at 1.5 psi
or greater for a minimum of 5 minutes. If the minimum 1.5
psi cannot be maintained for this period of time, then service
to the needle and seat is required.
Float Installation
Reinstall the inlet needle and float into the carburetor. The
long end of the spring or clip on the inlet needle must point
toward the air intake end of the carburetor. If a float
dampening spring is used, reassemble using the following
steps (diag. 50).
1. Place the float upside down.
2. Position the spring on the float with the long end around and to the back side of the float's center back tang. The ends
must point toward the choke end of the carburetor. Hook the inlet needle clip on the inside float tang so the clip end
points to the choke end of the carburetor (diag. 50).
3. Place the float, float spring, clip and inlet needle in position between the hinge legs of the carburetor. As the float
assembly nears the hinge legs, wind the outside end of the spring so it goes to the outside of the leg (counterclockwise
looking from the choke end).
22
RETAINER NUT
TORQUE NUT TO
50 IN. LBS. (5.65 Nm)
DRIVE IN UNTIL
SEAT RESTS ON
BODY SHOULDER
INLET NEEDLE
SEATS AT THIS
POINT
LONG END
OF CLIP
CHOKE
END
FLOAT
"O" RING
BRASS WASHER
SPRING
HIGH SPEED
ADJUSTMENT SCREW
47
5/32" FLAT PUNCH
SEAT
INSERT THIS
FACE FIRST
48
CLIP
OPEN END
OF CLIP
THROTTLE
END
49
WASHER
INLET SEAT
INLET NEEDLE
FLOAT SPRING
HINGE PIN
50