Toro AC-1 Service Manual page 18

b
b. Squeeze the throttle trigger. If the engine
falters or hesitates as
it
accelerates, turn the
idle speed mixture needle out (counterclock-
wise) 1/16 turn at a time until the engine ac-
celerates rapidly.
c. If the idle speed has changed significantly be-
cause of steps a. and b. above, readjust the
idle speed screw.
7. Final High Speed Mixture Setting:
Adjust the high speed mixture needle as follows:
a. Squeeze the throttle trigger and
run the unit at high speed for 3 to 5 minutes.
b. While squeezing the throttle trigger fully, set
the high speed mixture needle at the optimum
setting. See "Definition of Optimum Setting"
on page 1-1 5.
NOTE: The high speed mixture needle adjustment
must be the last adjustment made
on
the carburetor. If
the idle speed mixture needle is adjusted, the high
speed mixture needle must be readjusted.
8. Make sure the air filter cover is reinstalled securely
before placing the unit back into service.
For Units with Engine Serial Number 407000001
and Greater-Use the following carburetor adjust-
ment instructions:
1. Initial Idle Speed Setting: Back the idle speed
screw (Figure 1-15) out (counterclockwise) until
it does not contact the carburetor throttle lever.
Then turn the screw in (clockwise) until it just be-
gins to move the throttle lever; then continue turn-
ing 2 full turns.
2. Initial High Speed Mixture and idle Speed
Mixture Settings: Turn both the high speed mix-
ture and idle speed mixture needles in (clock-
wise) until they are lightly seated.
1-14
3. Turn the needles out (counterclockwise) the
following number of turns:
High Speed Mixture Needle: 1 1/8 turns
Idle Speed Mixture Needle1 1/8 turns
NOTE: Seat the high speed mixture and idle speed
mixture needles using finger pressure. Forcing the mix-
ture needles will damage the tips of the needles and
the seats in the carburetor body.
4.
Start the engine and let it run for
3
to 5 minutes
with the throttle lever fully squeezed.
5. Release the throttle trigger and let the engine idle.
If the engine stops, turn the idle speed screw in
~
(clockwise) 1/8 turn at a time (as required) until
the engine idles.
6. Final High Speed Mixture Needle Adjustment:
a. While squeezing the throttle trigger fully, set
the high speed mixture needle at the optimum
setting. See "Definition of Optimum Setting".
NOTE: After the final high speed mixture needle ad-
justment is made, no more high speed mixture needle
adjustments to the carburetor are necessary.
7. Final Idle Speed and Idle Speed Mixture
Adjustments: Adjust the idle speed screw and
'
idle speed mixture needle for the smoothest en-
gine idle using the following procedure. Do not
~
squeeze the throttle trigger when adjusting the idle
speed screw and idle speed mixture needle.
a. Set the idle speed mixture needle at the
~
optimum setting (Figure 1-16). See "Definition'
of Optimum Setting".
b. Turn the idle speed mixture needle out
(counterclockwise) 1/8 turn to the rich side
~
of optimum.The engine should idle and accel-
erate smoothly.