Idle Speed Adjustment; Replacing The Spark Plug - MTD YARD-MAN YM320BV Manuel De L'utilisateur

MAINTENANCE AND REPAIR INSTRUCTIONS

IDLE SPEED ADJUSTMENT

The idle speed of the engine is adjustable through the air
filter/muffler cover (Fig. 19).
NOTE: Careless adjustments can seriously damage your
unit. An authorized service dealer should make
carburetor adjustments.
WARNING:
idle speed adjustment. Wear protective
clothing and observe all safety instructions
to prevent serious personal injury.
Also, DO NOT set unit on any surface
except a clean, hard area while starting or
performing any adjustments. Debris such
as gravel, sand, dust, grass, etc. could be
picked up by the air intake and thrown out
by the discharge opening, damaging unit,
property, or causing serious injury to
bystanders or operator.
If after checking the fuel mixture and cleaning the air
filter the engine still will not idle, adjust the idle speed
adjuster as follows.
1. Start the engine and let it run at the fast position for
a minute to warm up.
2. Move the throttle control to the idle position and let
the engine idle. If the engine stops, insert a small
phillips or flat blade screwdriver into the hole in the
air filter/muffler cover (Fig. 19). Turn the idle speed
adjuster in, clockwise, 1/8 of a turn at a time (as
needed) until the engine idles smoothly.
3. If the unit appears to be idling too fast, turn the idle
speed adjuster counterclockwise 1/8 of a turn at a
time (as needed), to reduce idle speed.
Checking the fuel mixture, cleaning the air filter, and
adjusting the idle speed should solve most engine
problems. If not and all of the following are true:
• the engine will not idle
• the engine hesitates or stalls on acceleration
• there is a loss of engine power
Have the carburetor adjusted by an authorized service dealer.
Fig. 19
16
This unit will need
to be running during
Idle Speed Screw

REPLACING THE SPARK PLUG

Use a Champion ® RDJ7Y spark plug, or equivalent. The
correct air gap is 0.025 inch (0.635 mm).
1. Stop the engine and allow it to cool. Grasp the plug
wire firmly and pull it from the spark plug.
2. Clean around the spark plug. Remove the spark plug
from the cylinder head by turning a 5/8-inch socket
counterclockwise.
3. Replace a cracked, fouled or dirty spark plug. Set
the air gap at 0.025 in. (0.635 mm) using a feeler
gauge (Fig. 20).
WARNING:
electrodes. Grit in the engine could damage
the cylinder.
4. Install a correctly-gapped spark plug in the cylinder
head. Tighten by turning the 5/8-inch socket
clockwise until snug.
If using a torque wrench torque to:
110-120 in.•lb. (12.3-13.5 N•m)
Do not over tighten.
0.025 in.
(0.635 mm)
Fig. 20
Do not sand blast,
scrape or clean