Yamaha VIKING Owner's Manual page 134

Measure the spark plug gap with a wire thick-
ness gauge and, if necessary, adjust the gap
to specification.
8
a. Spark plug gap
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)
Installation
1. Clean the surface of the spark plug gas-
ket and its mating surface, and then wipe
off any grime from the spark plug
threads.
2. Install the spark plug and tighten it to the
specified torque. If a torque wrench is not
available when you are installing the
spark plug, a good estimate of the correct
torque is one-quarter to one-half turn
past finger tight. Have the spark plug
tightened to the specified torque as soon
as possible.
Tightening torque:
Spark plug:
13 Nm (1.3 m·kgf, 9.4 ft·lbf)
3. Install the spark plug cap.
4. Lower the cargo bed.
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