Service manual

G420F(FE) Service Manual Chapter 2. Recommended Maintenance 26
Inspection of Spark Plug
Inspection and clean
1) Ignition wire Ass’y
2) Ignition coil Ass’y
3) Spark plug
1. Disconnect the ignition wire ass’y from ignition
coil ass’y.
Remove the ignition coil ass’y by pulling the ignition
coil hand.
2. Remove all spark plugs from the cylinder head
using a sparkplug wrench.
CAUTION
Take care not to come foreign materials into
spark-plug mounting hole.
3. Check the spark plug as below.
1) Insulator broken
2) Terminal worn
3) Carbon deposit
4) Gasket damaged or broken
5) Porcelain insulator of spark plug clearance
4. Check the plug clearance using a plug clearance
gauge and if the value is not within the specified
values, adjust it by bending the ground clearance.
When installing a new sparkplug, install it after
checking the uniform plug clearance.
Spark plug clearance 0.7~0.8mm