Walker MT - Manual (Page 85)

Maintenance Instructions
ADJUSTMENTS
81
2. Preliminary Setting: Turn the idle mixture nee-
dle valve out (counterclockwise) 1-1/2 turns
from the closed position. This initial adjust-
ment will allow the engine to be started and
warmed up prior to the final adjustment.
Carburetor Adjustment
3. Start the engine and allow it to warm up by run-
ning at 1/2 throttle for approximately five (5)
minutes. The engine must be warm before
making final settings.
4. Move the throttle to the idle position. Adjust idle
speed for 1200 rpm (± 75 rpm) by adjusting the
idle speed screw. Check the idle speed using a
tachometer.
5. With the engine idling, adjust the idle mixture by
turning the idle mixture needle valve in (slowly)
from the preliminary setting until engine speed
decreases and then back out approximately 3/4
to 1 turn to obtain the best low speed perfor-
mance.
6. Recheck idle speed after the final idle mixture
adjustment.
GHS “Full” Signal Horn with Grass-Pak
®
Switch
If the GHS “full” signal horn is not sounding or is not
adjusted to sound when the catcher is full, the fol-
lowing troubleshooting and adjustment instructions
apply:
Troubleshooting (When Horn Fails to Operate)
1. Check the horn.
a. Disconnect the two wires from the Grass-
Pak
®
switch electric connector plug and
make a jumper wire connection between
these wires (bypassing switch).
b. Turn the ignition switch ON and move the
blade clutch to the ENGAGED position
(engine not running) to make the horn
sound.
c. If the horn does not sound, the horn is bad
and needs to be replaced.
d. If the horn does sound, proceed to step 2.
2. Check the Grass-Pak
®
switch.
a. Reconnect the wires to the Grass-Pak
®
switch electric connector plug.
b. Turn the ignition switch ON and move the
blade clutch to the ENGAGED position
(engine not running).
c. Open the catcher back door and trigger the
Grass-Pak
®
vane by hand as it oscillates.
d. The horn should sound as the switch is
moved in both directions. If the horn does
not sound, the switch is bad and needs to
be replaced.
DANGER
The engine must be running to adjust the
carburetor for engine idle. To guard
against injury, keep hands, feet, face, and
other parts of body away from the muffler/
exhaust pipe, other hot parts of the engine,
and moving or rotating parts of the engine.
Low Idle Mixture
Needle Valve
(May be Non-Adjustable)
Fixed Main Jet Under
Shutdown Solenoid
Idle Speed
Screw
WARNING
PINCH POINT - SPRING LOADED DOOR
When lowering the door on the GHS catch-
er, depress the safety latch on the side of
the catcher as the door closes. The springs
that hold the door closed during operation
are very powerful, and the door CAN slam
shut with considerable force.