Bolens 120-270A - Manual (Page 10)

THROTTLE
If adjustment becomes necessary, the throttle
control wire assembly can be reset as follows:
1. Loosen clamp at carburetor that holds the
cable housing. See figure 16.
2. Loosen the throttle cable (wire) at the car­
buretor throttie iever.
3. Move throttie controi iever to “FAST” posi­
tion.
4. Tighten clamp (step one) at carburetor.
5. Move throttle lever on carburetor to full open
throttle position and tighten screw that
clamps the cable (wire).
6. Check by moving throttle knob from fast to
slow several times. Cable housing should not
move in clamp. Throttle should open and
close fully.
Clamp
at Carburetor
Throttle
Control
Wire
FIGURE 16.
(Di
WARNING
j
If any adjustments are made to the
engine while the engine is running
(e.g. carburetor), disengage all
clutches and blades. Keep clear of
all moving parts. Be careful of
heated surfaces and muffler.
CARBURETOR ADJUSTMENTS (See figure 17)
Minor carburetor adjustment may be required to
compensate for differences in fuel, temperature,
altitude and load.
All carburetor adjustments should be made with
the air cleaner on engine. Air cleaner mounting
screw must be in carburetor when engine is run.
Best adjustment is made with a fuel tank half full
of gasoline.
To Adjust Carburetor:
1. Start engine and run long enough to warm it to
operating temperature.
If engine is out of adjustment so that it will
not start, close the needle valve by turning it
clockwise. Then open needle valve 1-1/2 turns
counterclockwise.
2. Move engine control to run engine at normal
operating speed.
a. Turn needle valve in clockwise until
engine starts to lose speed (lean mixture).
b. Then slowly turn needle valve out counter­
clockwise past the point of smoothest
operation until engine just begins to run
unevenly (rich mixture).
c. Turn needle valve back in clockwise very
slowly till engine runs evenly.
d. Final adjustment of the needle valve
should be slightly to the rich side (turn
counterclockwise) of the mid-point.
3. Move engine control to SLOW. Turn idle ad­
justing screw until a fast idle is obtained (1750
R.P.M.).
4. To check adjustment, move engine controi
from SLOW to FAST speed. Engine should ac­
celerate smoothly. If engine tends to stall or
die out, increase idle speed or readjust car­
buretor, usually to a slightly richer mixture.
FIGURE 17.
LUBRICATION
IMPORTANT
Always stop engine and disconnect
spark plug wire before cleaning,
lubricating or doing any kind of work
on lawn mower.
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