KYMCO AK 550 Service Manual page 198

6.Fuel System
AK 550
Measure the gap with a wire-type thickness gauge.
If the gap is incorrect, replace the spark plug.
Always check the gap of the spark plug before installation. Inspect the color of
the porcelain nose of the spark plug. The color of the spark plug can indicate how
the mixture is burning. A white colored plug shows a lean mixture, where a dark
plug shows a rich mixture. Do not hesitate to replace a spark plug. Always
replace a spark plug if any part of it is damaged.
Spark plug gap 0.7 - 0.8 mm
Do not over tighten the spark plug. The cylinder head is made out of soft metal,
and it can be easily damaged.
Item Torque
Spark plug 0.8~1.2 kgf-m
6-11