Power Unit; Checking The Fuel Filter; Checking The Spark Plug; Checking The Thermostat - Yamaha 55DEHD Service Manual

CHK
ADJ

Checking the fuel filter

1. Remove the nut, and then remove the
fuel filter assembly.
NOTE:
Be sure not to spill any fuel when removing
the fuel cap assembly.
2. Check the fuel filter element 1. Clean if
there is dirt or residue.
3. Check the fuel filter cup 2. Clean with
the straight gasoline if foreign substance
appears or replace if cracked.
2

Power unit

Checking the spark plug

1. Disconnect the spark plug caps, and then
remove the spark plugs.
2. Clean the electrodes 1 with a spark plug
cleaner and wire brush.
3. Check the electrodes 1 and gasket.
Replace the spark plug for erosion,
excessive carbon, other deposits or dam-
age.
3-3
Periodic check and adjustment
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4. Check the spark plug gap a. Adjust or
replace if out of specification.
Specified spark plug:
B8HS-10, BR8HS-10 (NGK)
Spark plug gap a:
0.9–1.0 mm (0.035–0.039 in)
5. Tighten the spark plug temporarily, and
then tighten it to the specified torque with
a spark plug wrench.
Spark plug:
25 N·m (2.5 kgf·m, 18 ft·lb)

Checking the thermostat

1. Remove the thermostat cover bolts 1,
thermostat cover 2, spring 3, PCV 4,
thermostat 5 and gasket 6.
6
2. Suspend the thermostat 5 in a container
with water.
a
6B430030
5
4
3
2
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