Mercury Outboard Ignition Parts
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Signs of a Failing Ignition System
Backfiring If your engine has recently begun to backfire, whether it is frequent or occasional, this is an obvious indication that the ignition coil needs to be replaced. The cause of a failing ignition coil most often occurs when unused fuel accidentally makes its way through the exhaust system. If you see black smoke coming from your engine or smell gasoline, that will tell you right away that the ignition coil, as well as the exhaust system are in need of immediate maintenance. Do not allow this problem to go unchecked for very long.
Fuel Economy If you start to notice a sudden drop in the mileage that you get per gallon, it comes back once again to the ignition coil. Your engine will use up more fuel as a result of faulty ignition coils, as well as spark plugs.
Misfiring If you begin to hear your engine cough and stall (and experience a rough ride as a result), then immediately inspect the state of your ignition coil. Also, if you notice that at higher speeds your boat and engine stall and jerk, this is a result of misfiring, and your ignition system should be repaired as soon as possible.
Starting the Engine Spark plugs and ignition coils are two of the most important components in an engine's ignition system, if not the entire engine as a whole. The two communicate with each other to build up and send electric charges through the system. If these parts do not communicate properly, they will not receive the full charge.
If you run unto trouble or feel you need assistance in this process, we urge you to contact your local dealer or mechanic. If you are new to boating, we do not recommend that this be attempted alone.
Ignition Parts and Systems
- Spark plug and wires – sparks the fuel and air mixture, igniting and starting the engine.
- Ignition coil – changes the voltage charge into a spark voltage ranging anywhere between 30,000-50,000 volts.
- Ignition tune-up kit – consists of hardware and components that help to maintain/repair the ignition system. Includes contact sets, condensers, etc.
- Stator – helps to maintain the charge in a battery, and also serves as the power supply to the ignition system.
- Distributor – an ignition component that consists of the shaft, rotor, and rotor shaft bearings.
- Pull start rope/rewind springs – the pull rope and rewind spring does not offer as much of a role in the ignition system. It enables you to get the engine turning fast enough to be able to start once the ignitions switch is turned on. Without the rotation of the engine, the coil, fuel and ignition can't fire.
- Trigger Assembly – this goes underneath the stator and sends electricity to the switch box and coils, which is generated by the flywheel and stator. Sends signals to timer base to ignite at the appropriate time.
- Wiring harness – connects the entire system together with wires; it harnesses energy between the entire system.
- Rectifier/Regulator – maintains, controls, and distributes battery voltage energy.
- Switch boxes – the switch box obtains, stores and releases energy in an outboard ignition system by way of a capacitive discharge. That is why these types of ignition systems are considered a "CD ignition system".
Diagnosing Your Mercury Ignition System
There are three primary portions in every Mercury engine that requires the most maintenance and regular inspections. The three portions are with fuel, air, and spark.
Fuel SystemUnless you are a technician or a boater with several years of experience, the process of inspecting and diagnosing the fuel system may seem confusing with the first try. Exercise caution here, because a problem that occurs within your fuel system may, in reality, be a problem with the ignition system. We do encourage you to consult with a technician or a local boat dealer. It would be wise to start off with a basic checkup on all fuel system parts– don't feel you have to dive right into diagnostics. Once you have observed the entire fuel system and have determined the existence of a defect in a certain system, you can either repair or replace the parts. Some of the more crucial components that require regular upkeep and repair are carburetors, fuel pumps, and fuel lines and connections. Do not jump to the conclusion that everything needs replacing; only the parts in critical disrepair should be replaced, not repaired. Some of the issues that could be contributing to faulty venting, loose connections, low supply between cylinders to the fuel pump, etc.
Air/CompressionChecking the compression section of your engine is undoubtedly one of the most important things to check off your list. Checking the compression system is something that needs a thorough inspection. Performing a compression is recommended, but even a good compression test reading can overlook certain problems. After testing it, we do recommend that you inspect the system (as you did with your fuel system) to verify whether or not there are any defects or breaks in any of the parts. Some of the parts you should pay especially close attention to in your observations are pistons, rings, and cylinders. Check for wear and tear, as well as the status of the internal structure. Perform a leak down test to determine the status of all of these components. Before the diagnostic test, make sure that the flywheel and all other components are securely fastened down. If you receive negative results, it may indicate idleness and damage in the compression system. If the compression/air system does need repair, a standard winterization cleanup will help to repair damage and prolong the life of this section, as well as the life of the engine as a whole.
Ignition SystemSome boaters are under the impression that the ignition system in an outboard marine engine is similar or identical to the layout in a standard automobile – however; this is not the case. Marine engines are unique in design and function, so be cautious when proceeding to inspect the ignition system. The status of the ignition system is especially crucial in the performance of the engine because it is all about timing and sparking the entire motor into action. Do not attempt to replace any damaged parts from the start, because ignition parts can be very expensive to replace. If the damage is mild enough, it can be repaired easily enough. However, if you are new to this, we do not recommend that you attempt this alone.
Please note, seek advice or guidance from a technician before attempting to diagnose and troubleshoot your engine.