Checking Fuel Filter; Inspecting Idling Speed - Yamaha 40X Owner's Manual

3. Be sure to use the specified spark plug,
otherwise the engine may not operate
properly. Before fitting the spark plug,
measure the electrode gap with a wire
thickness gauge; replace it if out of spec-
ification.
1. Spark plug gap
2. Spark plug I.D. mark (NGK)
3. Spark plug part number
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
4. When fitting the plug, wipe off any dirt
from the threads, and then screw it in to
the correct torque.
Spark plug torque:
25.0 Nm (2.55 kgf-m, 18.4 ft-lb)
TIP:
If a torque-wrench is not available when you
are fitting a spark plug, a good estimate of
the correct torque is 1/4 to 1/2 a turn past fin-
ger-tight. Have the spark plug adjusted to the
correct torque as soon as possible with a
torque-wrench.
EMU37450

Checking fuel filter

Check the fuel filter periodically. If any water
or foreign matter is found in the filter, clean or
replace it. For cleaning or replacement of the
fuel filter, consult your Yamaha dealer.
EMU29043

Inspecting idling speed

EWM00451
WARNING
Do not touch or remove electrical parts
G
when starting or during operation.
Keep hands, hair, and clothes away
G
from the flywheel and other rotating
parts while the engine is running.
ECM00490
NOTICE
This procedure must be performed while
the outboard motor is in the water. A
flushing attachment or test tank can be
used.
If the boat is not equipped with a tachometer
for the outboard motor, use a diagnostic ta-
chometer for this procedure. Results may
vary depending on whether testing is con-
ducted with the flushing attachment, in a test
tank, or with the outboard motor in the water.
1. Start the engine and allow it to warm up
fully in neutral until it is running smooth-
ly.
2. Once the engine has warmed up, verify
whether the idle speed is set to specifi-
cation. For idle speed specifications,
see page 9. If you have difficulty verify-
ing the idle speed, or the idle speed re-
Maintenance
ZMU06082
65