Inspecting Engine Idle Speed; Changing Engine Oil - Yamaha VF150 Owner's Manual

2. Measure the spark plug gap using a
thickness gauge. If the spark plug gap is
out of specification, replace the spark
plug with the specified plug.
1. Spark plug gap
2. Spark plug part number
3. Spark plug I.D. mark (NGK)
Spark plug gap:
1.0–1.1 mm (0.039–0.043 in)
To install the spark plug
1. Wipe off any dirt from the threads, insu-
lator, and gasket surface of the spark
plug.
2. Install the spark plug, and then tighten it
to the specified torque.
Spark plug tightening torque:
28 Nm (2.86 kgf-m, 20.7 ft-lb)
TIP:
If a torque-wrench is not available when you
are reinstalling a spark plug, a good estimate
of the correct torque is 1/12 turn past finger-
tight. When you are installing a new spark
plug, a good estimate of the correct torque is
1/2 to 2/3 turn past finger-tight.
3. Install the ignition coil, and then tighten
the bolt to the specified torque.
Bolt tightening torque:
8 Nm (0.82 kgf-m, 5.9 ft-lb)
4. Install the ignition coil cover.
EMU43962

Inspecting engine idle speed

ECM01691
NOTICE
This procedure must be performed while
the outboard motor is in the water.
Inspect the engine idle speed using the 6Y8
Multifunction tachometer or digital tachome-
ter that is equipped on the boat. Results may
vary depending on whether testing is con-
ducted with the outboard motor in the water.
1. Start the engine and allow it to warm up
fully in neutral until it is running smoothly.
2. Inspect the engine idle speed. If the en-
gine idle speed is out of specification,
consult a Yamaha dealer or other quali-
fied mechanic.
Idle speed (in neutral):
650–750 r/min
EMU44472

Changing engine oil

EWM00761
WARNING
 Avoid draining the engine oil immediate-
ly after stopping the engine. The oil is
hot and should be handled with care to
avoid burns.
 Be sure the outboard motor is securely
fastened to the transom or a stable
stand.
ECM01711
NOTICE
Change the engine oil after the first 20
hours of operation or 3 months, and every
100 hours or at 1-year intervals thereafter.
Otherwise the engine will wear quickly.
Maintenance
85