The engine is the powerhouse for the bike, and it is what makes it move. In a motorcycle engine, different motor parts combine to convert the fuel energy into mechanical energy, thus creating friction when they come in contact. As a biker, you know why engine oil is one of the most important fluids for your bike. Not only does it keep your motorcycle engine clean and running smoothly, but it also helps protect your engine from wear and tear. Whatever latest model or superbike you own, if the engine oil maintenance is not correctly and timely performed, it can ruin your riding experience. Now the question is, what happens if engine oil is overfilled in the bike? Too much oil in a motorcycle increases the pressure in the crankcase, forcing oil out of the engine and into the intake system. It can cause potential damage to the motorcycle engine and also burn oil in the engine.
Symptoms of too much oil in a motorcycle
To ensure smooth running and prolonged durability of your motorcycle engine, a routine engine oil change is very important. As per the amount specified in the owner manual, bikers must periodically change the engine oil as it not only ensures the healthy running of the motorcycle engine but also increases the running life of your motorcycle. Depending on the size of the engine, every bike requires a varying amount of engine oil and the same can be easily seen in your bike’s owner's manual.
Now when you or your mechanic has changed or refilled the engine oil, you often notice some of these below changes in the functioning of your motorbike when the engine oil has been filled over its capacity, i.e., when the engine oil is overfilled.
Oil leakage
Oil leakage happens when the engine oil seeps out of the engine, often through a small crack or hole. This seeping can cause the engine to overheat, as the oil will not be able to circulate correctly. With no proper lubrication of the engine parts, oil leakage can also lead to engine damage.
Smoky exhaust
Smoky exhaust due to too much oil in a motorcycle can cause the engine to run hotter than usual. The oil breaks down and causes deposits on the valves and pistons, which eventually restricts airflow and causes the engine to run less efficiently.
Fouled spark plug
When a spark plug becomes fouled, there is oil, fuel or carbon deposit on the tip of the spark plug. The deposit prevents the spark from jumping across the gap between the electrode and the ground, which causes the engine to misfire.
Signs of smoke from the exhaust area and the engine bay
Due to overfilling of engine oil, you may see smoke from the exhaust area because the oil is burning. When the oil burns, it creates a lot of smoke from the exhaust section.
Too much noise from the engine
The engine makes noise when the oil cannot circulate properly. It causes the engine to overheat and the engine oil to break down, resulting in the loss of lubrication and increased engine noise.
What happens if engine oil is overfilled in the bike?
In the owner manual, it is clearly stated: “Not to Overfill”. Unfortunately, there is no clear explanation of what will happen when the engine oil is overfilled? What harm will it have on my bike? In this later section of the blog, we will explain to you what happens when you accidentally overfill the engine oil above the stated limit and the risks it carries for your motorcycle.
Overfilling the engine oil can cause serious damage to your engine, but if you have filled the oil a few millimetres above the maximum sign, there is no need to worry. This is because of fact that the engine oil reserve of the motorcycle is designed to hold some extra engine oil which compensates for the fluid expansion that occurs due to hot conditions. Adding any more engine oil over this limit is bad for the engine.
When you add too much oil, the pressure on the crankcase increases. At the output shaft, this pressure might be well enough to rupture the oil seal if your engine’s crankcase would not have been vented via a rebreathable circuit. During normal operation, when the air inside the crankcase heats and cools, the rebreathable pumping balance the pressure inside the crankcase.
When you have overfilled the engine oil, the extra oil will go towards the crankshaft, and as the crankshaft keeps rotating at high speed, this oil gets mixed with air and becomes foamy causing a smoky exhaust. This works as a bad lubricant for the engine and due to this, the oil is not pumped efficiently. Over time due to the weak oil pumping, the engine can even get locked up.
