Mercury Marine is an international motor boat company based in Lake Forest, Illinois, providing motors for private, commercial and government craft. Mercury produces an extensive line of outboard motors. Like all mechanical equipment, Mercury motors can exhibit issues, ignition problems being some of the most worrisome.
Many ignition problems stem from electrical issues, but there are a few general troubleshooting tasks you should perform. Check that there is plenty of gas in the gas tank and that all fluid levels are at the right level. Make sure that all wires are connected properly. If there is no start from the engine, there may be no spark present. Check that the spark plug for the engine is free of decay and is clean. If there is any water on the spark plug, check for leaks.
1979 to 1997 Models
If the spark plug is working, disconnect the black/yellow wire and/or the black/white wire. These are the shorting and short circuit wires. Removing these allows you to troubleshoot the kill circuit. If the engine starts when these wires are disconnected, then the shorting system is faulty. If the engine does not start after disconnecting these wires, check the purple wire, which is the ignition switch wire, for damage and that it is secured properly.
1996 to Current Models
Try disconnecting the black/yellow wire from the engine to check the kill circuit first. If the engine still does not start, change the white/green and the green/white stator wire. This will change the engine starting cylinder. If the problem persists in the new cylinder, the stator is bad and needs to be changed.