LEHR BV025HH Operator's Manual page 14

MAINTENANCE
CARBURETOR ADJUSTMENT
The idle speed of the engine is adjustable. An idle
adjustment screw is on the rear side of the
carburetor (Fig. 20).
NOTE: Careless adjustments can seriously damage
your unit. An authorized service dealer should
make carburetor adjustments.
CLEAN AIR FILTER
The condition of the air lter is important to the
operation of the unit. A dirty or oil saturated air
lter will restrict air ow. This is often mistaken for
an out of adjustment carburetor. Check the
condition of the air lter before adjusting the idle
speed screw. Refer to Cleaning the Air Filter (p. 13).
ADJUST IDLE SPEED SCREW
If, after checking the fuel and cleaning the air lter,
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
(p. 10).
2. Release the throttle trigger and let the engine
idle. If the engine stops, use a small phillips or
at blade to turn the idle speed screw in,
clockwise, 1/8 of a turn at a time (as needed)
until the engine idles smoothly (Fig. 20).
NOTE: Checking the fuel, cleaning the air lter, 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.
Check the spark plug for proper gap and condition.
If problem still occurs, have the carburetor
adjusted by an authorized service dealer.
WARNING:
DO NOT SAND BLAST, SCRAPE, OR CLEAN
SPARK PLUG ELECTRODES. GRIT IN THE
ENGINE COULD DAMAGE THE CYLINDER.
LEHR |
14
ALL RIGHTS RESERVED 2009-2010
REPLACING THE SPARK PLUGS
Use a replacement part number NGK CMR6A, or
Champion RCJ6Y. The correct air gap is 0.02 in.
(0.5 mm). Remove the plug after every 25 hours of
operation and check its condition.
1. Stop the engine and allow it to cool. Remove the
spark plug cover. Grasp the plug wire rmly and
pull the cap from the spark plug.
2. Clean dirt from around the spark plug. Remove
the spark plug from the cylinder head by using
a 5/8 in. socket turning it counterclockwise.
3. Replace cracked, fouled or dirty spark plug. Set
the air gap at 0.02 in. (0.5 mm.) using a feeler
gauge (Fig. 21).
4. Install a correctly-gapped spark plug in the
cylinder head. Turn the 5/8 in. socket clockwise
until snug.
NOTE: If using a torque wrench torque to:
110-120 in. lb. (12.3-13.5 N-m). Do not over
tighten.
Idle
Adjustment
Screw
0.02 in.
(0.5 mm)
Fig. 20
Fig. 21