Checking The Spark Plug; Adjusting The Carburetor - Honda UMK425E1 Manuel Du Propriétaire

Both sides of 3-tooth and 4-tooth blades can be used.
When one side is worn, the cutting attachment should be turned
over to use the cutting edges on the other side.
Only the bevelled edges of the teeth are to be sharpened.
It is important to keep their profile regular and to avoid incipient
fractures.
All the teeth must be sharpened in the same way.
NOTE: If the machine vibrates abnormally after sharpening, this
indicates that the blade is unbalanced. In this case, contact your
authorized dealer Honda to have it checked.
CAUTION:
• Replace the blade when the wear limit shown in the illustrations
below has been reached.
[A] Unsatisfactory
[1] Incipient fracture
[2] Limit exceeded and
tooth profile irregular
[3] Angles incorrect and unequal
[4] Unsatisfactory cutting profile
[B] Satisfactory
[5] Sharpening limit

ADJUSTING THE CARBURETOR

PROCEDURE
Start the engine and let it warm up to normal operating temperature.
Then turn the idle screw [7] to the right or left to obtain the correct
setting.
Idle speed
NOTE: When the engine is idling, the cutting attachment must not
rotate.
[A]
[4]
[B]
30°
30°
[7]
UMK425E1 UMK435E1
3 100 ± 200 rpm.

CHECKING THE SPARK PLUG

1. To reach the spark plug [8],
the top cover must be
removed from the
engine [9]. Use the
hexagonal wrench supplied
to undo the bolt [10].
[2]
[1]
NOTE: Hot parts and moving parts (flywheel) are exposed when the
engine top cover is removed. Never use your brush cutter with the
[3]
engine cover removed.
2. Remove the cap and unscrew the spark plug using the wrench
supplied.
3. Clean the electrodes with a wire brush [11] to remove carbon
deposits.
30 mm
[5]
4. If the electrodes show signs of wear, replace the spark plug with
a new one with the same characteristics.
5. Check the spark plug gap
with feeler gauges [12].
30°
When adjustment is
required, carefully bend the
30°
side electrode.
6. Reinstall the spark plug and
screw it finger-tight onto its
seat.
7. For new spark plugs,
tighten by an additional 1/2
turn with the spark plug
wrench.When the same
spark plus is installed, 1/8 to 1/4 of a turn is enough.
CAUTION:
• If a spark plug is insufficiently tightened, it is liable to heat up and
damage the engine. If the spark plug is overtightened or cross-
threaded, irreparable damage could be caused to the engine
block.
B7 C1
SAFETY
[9]
[8]
[10]
[11]
0,6-0,7 mm
[12]
9 EN