HYOSUNG 2010 ST7 Service Manual page 24

▣ ▣ CARBON DEPOSITS
Check to see if there are carbon deposits on the
spark plug.
If carbon is deposited, remove it using a wire or pin
with a pointed end.
▣ ▣ SPARK PLUG GAP
Measure the spark plug gap using a thickness
gauge.
If the spark plug gap is out of specification, adjust the
gap.
Spark plug gap
Thickness gauge : 09900-20806
▣ ▣ ELECTRODE
Check to see the worn or burnt condition of the elec-
trodes.
If it is extremly worn or burnt, replace the spark plug
with a new one.
And also replace the spark plug if it has a broken
insulator, damaged thread, etc.
CAUTION
To avoid damaging the cylinder head threads ;
first, finger tighten the spark plug, and then tight-
en it to the specified torque using the spark plug
wrench.
● Insert the spark plug and finger tighten it to the
cylinder head and then tighten it to the specified
torque.
Spark plug : 11 N· · m (1.1 kgf· · m)
0.7 ∼ 0.8 mm (0.028 ~ 0.032 in)
PERIODIC MAINTENANCE 2-6
0.7 0.8 mm
(0.028 0.032 in)