How to Buy Motorcycle Engine Parts on eBay

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How to Buy Motorcycle Engine Parts on eBay

A motorcycle might look smaller than a car, but its engine requires equal attention. Keeping a motorcycle in top shape protects the initial investment made on the day it was bought. Maintaining the running condition of the engine usually requires a lot of work or many trips to the mechanic. Aside from the regular oil and coolant fluid changes, the prompt replacement of worn out and defective parts should be the first thing on the list of those who wish to preserve the state of an engine.

eBay is a good starting point for anyone looking to find a specific engine part as it offers a fine selection on all makes and models. Choosing the right part might sound like the job for a mechanic, but there are many out there who wish to care for their bikes themselves. To make the right decision, knowledge about the engine is required along with some information on the longevity of use that can be expected. With this information, the process of purchasing an engine part is a breeze.

Cylinder Head and Block of a Motorcycle Engine

The cylinder head and the cylinder block are two massive parts of a motorcycle engine. One should keep this fact in mind, as it makes these parts both heavy and pricey. Replacing a head or a block can be an expensive venture, and this makes both the supply and demand of the parts a bit scarce.

Cylinder Head

The cylinder head is the lighter and less expensive of the two components mentioned above. It sits on top of the cylinder, forming the combustion chamber. The state and the shape of the cylinder head largely influence the combustion efficiency. Needless to say that absolute compatibility is required between the cylinder head and body. The model number is usually present on the outside, so it is fairly easy to determine what to look for. Those on tight budgets can even consider purchasing this component from eBay's used market.

Cylinder Block

The cylinder block or engine block represents the whole structure of a cylinder; sometimes, it even refers to the surrounding system that composes an engine. When a bike reconstruction or restoration is done, the cylinder block is usually retained, as there are not many reasons for purchasing and changing the whole unit. Still, there are some offers to be found on eBay, and they might be worth considering by those who wish to build a motorcycle from scratch.

Head Gasket of a Motorcycle Engine

The head gasket of a motorcycle engine is a very important part. It is a thin piece of metal, covered in rubber, that sits between the cylinder head and the engine block and provides a tight seal between these two parts. This component maintains engine compression and prevents engine fluids from mixing. Loss of compression and fluid mixing significantly influence the way an engine runs, and this can also cause permanent engine damage. This is why it is considered good practice to replace the head gasket any time major engine interventions are made. Finding a compatible one on eBay is simple and only requires knowledge of the engine type.

Interior Parts of a Motorcycle Engine

Many parts require disassembly of large sections of the engine in order to be replaced. Some of them wear out faster than others, but all of them need to be replaced sooner or later. A short list of the motorcycle engine interior parts usually sought on eBay is provided in the chart below.



Top Rocker Arm

A lever that works with the valve spring to open and close the valve.

Bottom Rocker Arm

Regulates the speed of the pistons and rests on top of the camshaft.


Makes the connection to the transmission and regulates the speed.

Lifter Rod

A rod placed between the two rocker arms.

Valve Spring

A spring that pushes the valve stem back into position after a stroke.


Performs compression in the cylinder.

The above list makes up only a small portion of the parts that form an engine. Each part plays an important role in the design, but some of them are more unique to a model than other. Nuts and bolts are universal and raise no compatibility issues.

Arms, Rods, and Springs

The size of all these parts is generally determined by the cylinder. This means that all of them are very dependent on the engine model. Some of them are even sold fitted to one another for quicker and more accurate assembly. They can be purchased in the new or old condition. It is to be noted that these are all movement components, so they are more likely to be worn out than the static ones.

Pistons and Piston Rings

Pistons and piston heads are two names representing the same thing. They are a part of the interior mechanism of a cylinder responsible for fuel compression. The piston rings surround the piston and act both as interior gaskets and friction protectors. A great deal of the performance of a piston is dependent on the piston ring. Replacing the piston rings rather than the piston is both easier and cost effective. To select the right piston ring, eBay buyers need to be aware of the types of piston they are dealing with. The ring is a tight fit, it is important to have the right one. The same rule goes for the purchase of a piston. If there is any doubt about the model number, find detailed specifications of the cylinder. All information is usually offered there. Buyers can even benefit from purchasing used pistons. A solid used piston can still serve its purpose for many years.

Spark Plugs and Caps

Spark plugs are one of the unique engine parts that can be accessed and replaced from the outside. A number of spark plugs to be found on eBay, but usually only a handful fit a specific type of engine. To choose the right plug, follow the manufacturer's instructions. Selecting the wrong plug can lead to bad fuel consumption, engine misfires, and starting problems, so it is a good idea to trust the recommendations of those who designed the engine. There are some spark plugs with more universal application, but some engines can also run on just one specific plug model.

Always measure the spark plug gap to determine whether a compatible plug is right for the engine. The gap of the replacement plug should be the same width as the one being replaced. A gap bigger or smaller than that is no good. The gap is usually noted among the product specifications, so be sure to select the right one.

The cap that goes over the plug is equally important as the plug itself. Due to the external visibility of plugs, many motorcycle owners feel tempted to use decorative spark plug caps. This type of caps might be easy on the eye, but they can lower the power of the spark plug and weaken the spark system. A better approach to spark plug caps is to always use regular ones and select a style that is agreeable with the angle created by wire and the plug. Commonly encountered spark plugs on eBay include the 'X' style, 'L' style, 'V' style, and the 'S' style. Each style has its own specific angle, though the height of the cap might vary.

Buying Motorcycle Engine Parts on eBay

For those who wish to find motorcycle engine parts, the eBay Motors section of eBay is a great choice, as this section deals exclusively with vehicles. From there, a buyer can easily navigate through the 'Motorcycle Parts & Accessories' category and reach the 'Motorcycle Parts' section. Within this section, a list of multiple motorcycle makes is provided. By selecting the one of interest, eBay generates a list of all the related parts. One can narrow down the selection to just engine parts by using the 'Engine parts' filter.

Using the search bar is a quick way to reach a desired item. Just entering the name of the item as a query delivers relevant results. Those who wish to search for parts in general can enter relevant terms like 'engine parts' and then use the selection of filters and categories to browse through the offers. The condition of the parts can be filtered as well. The 'new' and 'used' filters come very handy when making a comparison on how much money can be saved on a purchase.


In the end, it all comes down to compatibility and condition when purchasing motorcycle engine parts on eBay. Those who wish to purchase engine parts for motorcycles on the website should pay close attention to get a close fit for a part and ensure that it is functioning, especially if it is a used part. Some parts are more universal than others, but the majority of the inside components of an engine are uniquely built to fit a specific model.

The two big engine parts purchases one can make are the cylinder head and the engine block. If well maintained, these items can serve their purpose for many years. The same goes for many of the engine interior mechanics like pistons arms, rods, and springs. Components like the head gasket, spark plugs, spark cups, or piston rings are considered to be expendable, which means that they should be bought brand new. There is not much money to be saved on purchasing slightly used ones, as the expendable nature of these engine parts usually makes them generally less expensive. No matter what one's need, eBay's vast resources and functionalities can help potential buyers locate the right parts at great prices.

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