Mercury outboard engines have been considered one of the most reliable and durable engines for boating enthusiasts. If you own a 115 HP Mercury outboard engine and require guidance in wiring its ignition system, this article will assist you in understanding the wiring diagram.
Understanding the Wiring Diagram
The wiring diagram for a 115 HP Mercury outboard engine consists of various components such as the battery, starter motor, ignition switch, choke solenoid, fuel pump, and the engine control module (ECM).
The ignition system comprises of two types of circuits, primary and secondary. The primary circuit includes the battery, ignition switch and the coil, while the secondary circuit comprises of the spark plug, distributor cap, rotor and the spark plug wires.
The ignition switch is used to turn on and off the engine. By turning the ignition key, the battery supplies power to the primary circuit, which in turn generates a magnetic field in the coil. When the ignition key is released, the magnetic field collapses, causing a high voltage current to be produced in the secondary circuit. This high voltage current flows through the spark plug wire, igniting the fuel mixture in the engine cylinder.
115 HP Mercury Outboard Ignition Wiring Diagram
The ignition wiring diagram for the 115 HP Mercury outboard engine is shown below:
| Component | Wire Color | Pin Number |
|---|---|---|
| Battery | Red | – |
| Ignition Switch | Yellow/Red | – |
| Choke Solenoid | Yellow/Green | – |
| Fuel Pump | Orange/Blue | – |
| Engine Control Module (ECM) | Black/White | – |
| Starter Motor | Purple | – |
| Coil | Green/Blue | – |
| Spark Plug Wire | Black/White | – |
Frequently Asked Questions
What is the purpose of the choke solenoid?
The choke solenoid is used to enrich the fuel mixture in the engine cylinder during startup. When the engine is cold, the fuel mixture needs more fuel to ignite. The choke solenoid restricts the air intake, creating a richer fuel mixture, which ignites easily. As the engine warms up, the choke solenoid opens up, allowing more air into the engine, making the fuel mixture leaner.
What is the role of the engine control module (ECM)?
The engine control module (ECM) is a device that controls various functions of the engine such as timing, fuel injection, and ignition timing. It receives input from various sensors such as the throttle position sensor, coolant temperature sensor, and oxygen sensor, and regulates the engine performance accordingly.
What is the function of the spark plug?
The spark plug is a device that creates a spark to ignite the fuel mixture in the engine cylinder. It consists of two electrodes, a central electrode and a ground electrode. The high voltage current generated in the secondary circuit flows through the spark plug wire, creating a spark between the electrodes, which ignites the fuel mixture in the engine cylinder.
How do I troubleshoot ignition system problems in my 115 HP Mercury outboard engine?
If you are experiencing ignition system problems in your 115 HP Mercury outboard engine, the first step is to check the battery voltage. If the battery is weak or dead, the engine will not start. If the battery is fine, check the spark plug for signs of wear or damage. If the spark plug is fine, check the ignition coil and the spark plug wire. A fault in any of these components can cause ignition system problems.
What is the recommended maintenance schedule for the ignition system in my 115 HP Mercury outboard engine?
The ignition system in your 115 HP Mercury outboard engine should be inspected and serviced regularly. The spark plug should be checked for wear and replaced if necessary. The ignition coil and spark plug wire should also be inspected for signs of wear and damage. The battery terminals should be cleaned and tightened at regular intervals. The fuel filter should be replaced every 100 hours of operation. Regular maintenance of the ignition system will ensure trouble-free operation of your engine.
In conclusion, understanding the ignition wiring diagram is crucial in troubleshooting and maintaining your 115 HP Mercury outboard engine’s ignition system. Regular maintenance and timely troubleshooting will ensure reliable and efficient engine performance, making your boating experience enjoyable and safe.
