Chrysler 20 and 30 HP Outboard Motors Service Manual OB 3435, Page 79Get this manual
SPARK PLUGS DescriptionA spark plug consists of two electrodes separated from each other by an air gap The side electrode is connected to the shell of the spark plug The center electrode is completely insulated from the shell
The high voltage, produced in the secondary coil winding (located in the C-O module), is applied to the center electrode and causes spark to jump the gap to the side electrode This spark ignites the fuelair mixture and starts the combustion process in the cylinderThe gap between electrodes is critical because it affects the entire range of engine performance starting, idlingaccelerating, power and top speed RemovalUse 13 16" deep well socket with ru bber
insert to protect spark plug insulation InspectionIn nearly every case of spark plug failure, the cause must be corrected before new spark plugs are installed Otherwise, servicing will be needed again in short time
Figure 23Connecting C-D Leads