Doosan G643E - Page 28

G643(E) Service Manual Chapter 2. Recommended Maintenance 26
S
park Plugs
5. Install the spark plug and tighten it to the specified
torque.
Take care not to over tighten it to prevent cylinder
head threads from damage.
Tightening torque 25~30 N•m
SPARK PLUG ANALYSIS
State Contact point is
black
Contact point is
white
Description • Density of the
fuel mixture is
thick
• Density of the
fuel mixture is
thin
• Lack of air
intake
• Ignition timing is
fast
• Spark plug is
tight
• Lack of torque