#Inboard outboard mercruiser how to
#Inboard outboard mercruiser full

It is important they go back onto the same plug they came off of or the engine will not run properly, if at all. This can be done by labeling the wires as they are removed. Tip: Keep track of the location of each plug wire. The metal clip inside will simply pop off and the boot will pull off of the plug. Grip the spark plug cable boot firmly and pull straight out while twisting back and forth. An 8 cylinder engine will be similar except 1 additional plug on each side. Below are pictures of the spark plug locations for both the port and starboard side of a 4.3l engine. In this example, the 4.3l Mercruiser engine is a 6 cylinder engine so there will be 3 spark plugs on each side of the engine. The spark plugs will be evenly distributed on both sides of the engine. This is done differently depending on your boat, but if you have a 4.3l, typically there is an engine cover or hatch that can be lifted away from the engine to perform maintenance on it. The first step to change your boats spark plugs is to access the engine. For example a 5.0l engine has 8 cylinders, therefore 8 spark plugs, but the procedure is the similar. Other engine spark plug changes are performed in a similar matter, they are typically just located in a different position or have a different number of plugs.

#Inboard outboard mercruiser how to

In the guide below we show where these are located and how to change them. On a 4.3l Mercruiser engine there are six cylinders, therefore, six spark plugs. Steps to Change the Spark Plugs on a 4.3l Mercruiser Checking a spark plug can be useful as they can show signs of issues such as running rich, running lean, oil leaks, and more. If you don’t put a significant amount of hours on your boat, we still recommend inspecting the spark plugs each year not only to make sure they are in good shape, but to also ensure there are no other issues with your boats engine.

This is the recommendation that Mercruiser gives as well for their engines specifically. Most manufacturers recommend changing the spark plugs on an inboard engine once every 300 hours or every 3 years, whichever comes first. How Often Should You Change the Spark Plugs on a Boat? These different failure modes are discussed below. The best way to avoid this is to do a routine spark plug change, however, there are some other issues with an engine that may cause certain types of spark plug failures or fouling. If this mixture does not properly ignite, your engine will not produce power on all cylinders, run rough, and have less power. If the spark on a spark plug becomes weak, or non-existent, the air and fuel mixture in the combustion chamber will not ignite fully, or even at all. A spark plug can be worn out in many different forms, but the end result of each scenario is the inability for the plug to have a clean strong spark. Why is it Important to Change the Spark Plugs on an Engine?Īs your engine is used, hours of spark, fuel, and combustions will eventually cause a spark plug to be worn out. The most common method is delivery through spark plug wires, but newer engines also have coil packs mounted directly on top of the spark plugs. On the opposite side there is a terminal either a spark plug wire, or coil pack, is connected to depending on the style engine that is in your boat. On this end, there is a central electrode that receives current, and a ground electrode that this current arcs to, creating the spark. The spark that is delivered happens at the end of the spark plug that is inside of the cylinder combustion chamber.

This causes an explosion that pushes the piston in the cylinder area and rotates the crank. At this point, the system delivers a spark to ignite this air and fuel mixture.

#Inboard outboard mercruiser full

Once a piston is on the combustion stroke, the cylinder cavity will be full of an air and fuel mixture. As the engines rotating assembly rotates, the pistons go through different strokes.