MTD BL100/BL150 Trimmer User Manual


 
15
MAINTENANCE AND REPAIR INSTRUCTIONS
SPARK ARRESTOR MAINTENANCE
1. Remove air filter/muffler cover. Refer to
Removing the Air Filter/Muffler Cover.
2. Locate the muffler, but do not remove
it. Find the screw on the bottom of
the muffler (Fig. 26). Remove the
screw using either a torx #20 or flat
blade screwdriver.
3. Carefully pry up the left side spark
arrestor hood. Two tabs act as hinges
on the right side of the hood. Flip
open the spark arrestor hood like a
door and then pull its tabs out of the
muffler slots.
4. Using a small flat blade screwdriver,
carefully pry the spark arrestor screen
out from the inside of the spark
arrestor hood.
5. C
lean the spark arrestor screen with a
wire brush. Replace it if it is damaged, or
if you are unable to clean it thoroughly.
6. R
einstall the spark arrestor screen snugly
back into the spark arrestor hood.
7. Reinstall the two hood tabs into the
two muffler slots and flip the spark
arrestor hood closed.
8. Replace the screw you removed in
Step 2 and tighten it securely.
9. Reinstall the air filter/muffler cover.
CARBURETOR ADJUSTMENT
The idle speed of the engine is adjustable
through the air filter/muffler cover (Fig. 27).
NOTE: Careless adjustments can
seriously damage your unit. An
authorized service dealer should
WARNING:
If the spark
arrestor hood and spark arrestor
screen are not tightened
securely, they could fall off
causing damage to the unit and
possible serious personal injury.
Fig. 26
Tabs
Screw
Spark Arrestor
Hood
Spark Arrestor
Screen
Slots
make carburetor adjustments.
CHECK FUEL MIXTURE
Old and/or improperly mixed fuel is usually
the reason for improper unit performance.
Drain and refill the tank with fresh, properly-
mixed fuel prior to making any adjustments.
Refer to Oil and Fuel Information.
CLEAN AIR FILTER
The condition of the air filter is important to
the operation of the unit. A dirty air filter will
restrict air flow and change the air/fuel
mixture. This is often mistaken for an out of
adjustment carburetor. Check the condition
of the air filter before adjusting the idle
speed screw. Refer to Air Filter Maintenance.
ADJUST IDLE SPEED SCREW
If, after checking the fuel mixture and
cleaning the air filter, the engine still will not
idle, adjust the idle speed screw as follows:
1. Start the engine and let it run at a high
idle for a minute to warm up. Refer to
Starting/Stopping Instructions.
2. R
elease the throttle trigger and let the
engine idle. If the engine stops, insert a
small phillips screwdriver into the hole in
the air filter/muffler cover (Fig. 27). Turn
the idle speed screw in, clockwise, 1/8
of a turn at a time (as needed) until the
engine idles smoothly.
3. If the engine appears to be idling too
fast, turn the idle speed screw
counterclockwise 1/8 of a turn at a
time (as needed), to reduce idle speed.
WARNING:
The cutting
attachment will spin during idle
speed adjustments. Wear
protective clothing and observe
all safety instructions to
prevent serious personal injury.
Fig. 27