[Permanent Preservation] A Comprehensive Guide to Motorcycle Engine Oil: Selection, Replacement, and Recommendations!

How to Choose Engine Oil for Motorcycles

There are various types of motorcycle engine oil, and you need to choose the one that is compatible with your motorcycle.
This section explains how to choose the right motorcycle engine oil for your bike and riding environment. Please use this guide to find the optimal oil for your motorcycle.

Choose motorcycle oil according to the engine stroke

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Motorcycle engine oils come in two types: "4-stroke (4T)" and "2-stroke (2T)".
If you put in the wrong type, the engine may not start or may seize, so choose engine oil appropriate for your motorcycle.
4-stroke oil is solely for lubricating the engine, but 2-stroke oil, in addition to engine lubrication, is mixed with gasoline and burned, so it also requires good miscibility with gasoline.
If you accidentally put in engine oil for a different stroke type, do not continue riding and consult a motorcycle shop.
Whether it's for 4-stroke or 2-stroke is indicated on the oil container, so you can check the label.

4-strokes require oil changes, 2-strokes require replenishment

Like cars, 4-stroke oil requires regular oil changes, but 2-stroke oil is continuously burned, so it does not need to be changed.
For 2-stroke engines, regular oil replenishment is necessary, similar to refueling with gasoline.
If you ride without replenishing the oil, the engine will not be properly lubricated, and in the worst case, the engine could seize.
For 2-stroke motorcycles, regularly check the engine oil level and replenish it.

For 4-stroke oil, choose "MA" or "MB" according to JASO standards

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Motorcycle engine oils have JASO standards determined by their friction characteristics, categorized as "MA" and "MB".
Choose MB for scooters, which have a low friction coefficient, and MA for manual transmission (MT) vehicles, which have a high friction coefficient.
MA is divided into three subcategories: "MA", "MA1", and "MA2". Some motorcycles specify the use of MA1 or MA2.
For high-performance large motorcycles, it's safer to choose MA2 even if there's no specific designation.
The classification of engine oils by JASO standards is summarized in the table below.

JASO Standards and Criteria for Choosing Engine Oil
4-stroke JASO Standard Selection Criteria
MA High friction characteristics, for MT vehicles if MA1 or MA2 are not specified.
MA1 Within the MA friction characteristic range, with lower viscosity. For vehicles specifying MA1.
MA2 Within the MA friction characteristic range, with higher viscosity. For vehicles specifying MA2.
MB Low friction characteristics, suitable for scooters.
It is necessary to choose the appropriate engine oil for your vehicle, and JASO standards are the criteria for this selection.
When choosing engine oil, do not choose based on price, but rather based on the JASO standard criteria for your motorcycle.

2-stroke engine oil is also categorized by standards

2-stroke motorcycle engine oils are divided into four standards from FA to FD, with FA being the oil that meets the minimum required standards for 2-stroke oil.
FD is the highest-performance oil, which suppresses exhaust gas emissions and boasts high cleaning power, making it the highest quality 2-stroke oil.

JASO Standards and 2-stroke Engine Oil Specification Details
2-stroke JASO Standard Specification Details
FA Meets the minimum necessary standards for 2-stroke oil
FB Oil with better lubricity and cleaning performance than FA
FC In addition to FB performance, oil with even lower exhaust gas emissions
FD In addition to FC performance, oil with enhanced internal engine cleaning
In the global ISO standard for 2-stroke oils, FB corresponds to "GB", FC to "EGC", and FD to "EGD".
For daily riding and touring, it is recommended to choose FC or FD standard oil. For high-performance 2-stroke motorcycles like sport bikes, FD standard oil is a good choice.
Incidentally, Honda's most standard genuine 2-stroke oil "Ultra 2 Super" and Yamaha's genuine "Autolube Super Business Oil" are FC standard. From this, it is advisable to choose at least FC standard.

Choose a base oil according to its intended use

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There are three types of base oils: "mineral oil," "semi-synthetic oil," and "fully synthetic oil," with fully synthetic oil being the most expensive. Choose a base oil that suits your motorcycle's usage environment.
Oils contain additives to maintain lubrication and clean the engine interior.
Since the base oil forms the foundation for oil quality, choose an oil that matches your usage environment.
The expected usage environments and suitable base oils are as follows:

For commuting to work or school

If you mainly use your motorcycle for commuting, "mineral oil" is a good choice.
Mineral oil provides the minimum necessary performance and is cost-effective.
If you rarely engage in hard riding, it's advisable to choose mineral oil and change it frequently.
While mineral oil offers only basic performance, it is the least expensive of the three types of base oils, making it the most affordable oil with low running costs.

For circuit racing or high-speed driving

If you frequently ride on circuits or at high speeds, you should choose "fully synthetic oil."
When the engine is often revved at high RPMs, it is exposed to higher temperatures. Fully synthetic oil has high lubricating and heat resistance properties, making it less likely to break down its oil film even when the engine gets hot.
Fully synthetic oil is the most expensive of the three types of base oils, but it is designed to maximize engine performance.
Also, after circuit riding, it is advisable to change the oil as soon as possible, regardless of mileage.
Oil exposed to high temperatures for a long time can degrade its additives, making it difficult to maintain the oil film.
Especially in summer, oil temperatures tend to rise, so it's best to change the oil promptly after hard riding on a circuit.
Small displacement vehicles and mini bikes, which have less oil, put a greater strain on the engine, so more frequent oil changes are necessary.
If you participate in races, change the oil after each race, regardless of displacement.

For touring

"Semi-synthetic oil" is suitable for frequent touring.
Semi-synthetic oil is an intermediate between mineral oil and fully synthetic oil. It is made by blending about 20% fully synthetic oil into mineral oil, which helps to compensate for mineral oil's weaknesses, such as its poor heat resistance and tendency to oxidize.
It offers better performance than mineral oil and is not as expensive as fully synthetic oil, making it a cost-effective base oil.
If you want to protect your engine or maximize its performance, even for commuting or school rides, semi-synthetic oil is a good choice.

SEA Standard! Choose viscosity according to the environment of use

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Motorcycle engine oil viscosity is identified by the "SEA standard" and is expressed as "10W-30", "15W-40", etc.
The number before "W" indicates low-temperature viscosity, and the number after the hyphen indicates high-temperature viscosity. Let's look closer at what each means.

Low-temperature viscosity

The "W" in "10W-30," "15W-40," etc., displayed according to the SEA standard, stands for Winter, and the number before the "W" indicates the low-temperature viscosity. Low-temperature viscosity is an index that shows how much viscosity the oil maintains when cold.
The smaller the number, the lower (thinner) the oil viscosity, which means better engine starting performance in cold weather and better fuel efficiency.

High-temperature viscosity

The number after the hyphen represents the high-temperature viscosity, and a larger number indicates a higher (thicker) oil viscosity.
Oils with higher high-temperature viscosity offer better protection, such as less oil film breakdown even when the engine is hot, and also reduce noise.
Especially for sports riding like on a circuit, choose oils with high high-temperature viscosity such as "15W-50".
For good balance, an oil around "5W-40" is a good choice, offering good starting performance at low temperatures and excellent engine protection at high temperatures.

Choose a capacity that can be used within 1 to 2 years.

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Oil oxidizes when exposed to air, so when purchasing engine oil, choose a capacity that you can use within 1 to 2 years.
For regular riding, an oil change is recommended every 3,000 to 5,000 km or every six months, so determine the oil capacity based on your oil change cycle.
To slow down oil degradation, store remaining oil in a cool, dry place away from direct sunlight. Pay attention to storage conditions.

For severe conditions, early oil change is recommended

"Severe conditions" refer to driving conditions that are harsher for the motorcycle, such as annual mileage exceeding 20,000 km, driving on rough roads that cause jarring, driving on mountainous roads with many climbs, or frequent short trips (less than 10 km) like going to nearby shops.
Under severe conditions, the oil degrades faster, so oil changes need to be done more frequently than the mileage or semi-annual guideline.

How to change motorcycle engine oil: procedure explained!

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Changing motorcycle engine oil is relatively easy if you know the steps.
Here, we explain everything about engine oil changes and the procedure, so learn the method and give it a try.

Why is motorcycle oil change necessary? What happens if it's not changed?

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Motorcycle oil has five roles: "lubrication," "sealing," "cooling," "rust prevention," and "cleaning" to flush out combustion residues like carbon and sludge that result from engine combustion.
If the oil is not changed, residues and dirt will accumulate in the engine, affecting lubrication and cooling, which can prevent the engine from functioning properly.
Furthermore, fine metal particles generated by friction between metal parts mix into the oil, potentially causing damage such as scratches inside the engine.
Oil degradation also makes oil film breakdown more likely, and in the worst case, the engine may seize or overheat.
The resistance from residues and other build-up will also increase, negatively impacting fuel efficiency.

When is the exchange period? Is there a guideline?

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Engine oil should be changed every 3,000 to 5,000 km or every six months.
Change it based on whichever comes first: mileage or six months.
However, if you frequently ride on rough roads, mountainous roads with many climbs, or make repeated short trips (less than 10 km), these are severe conditions for the motorcycle, and oil degradation will accelerate.
If you fall under severe conditions, change the oil earlier than the guideline.

When is it time to replace the element/filter?

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The element/filter should generally be replaced every other oil change.
The element/filter plays the role of filtering and removing dirt contained in the oil due to engine combustion. If it is not replaced, its filtration ability will decrease, and dirt in the engine will not be effectively removed.
Remember to replace the element/filter just as you would the engine oil.

About oil changes and break-in periods for new motorcycle purchases

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While motorcycles are made up of numerous metal parts, these parts are not yet fully settled when the bike is new.
The same applies to the inside of the engine; parts may not have fully seated against each other, or there may be small metal burrs (tiny metal protrusions left after machining).
Therefore, when a bike is new, burrs are more likely to come off due to friction between parts inside the engine, requiring earlier engine oil changes than usual.
As a guideline, change the oil when the mileage reaches 1,000 km or one month after purchase, whichever comes first.

Is a break-in period necessary or unnecessary?

New motorcycles are said to require a break-in period to allow the engine parts to seat properly.
On the other hand, some argue that in the past, parts weren't as precise, so a break-in was necessary, but now that precision has greatly improved, a break-in is no longer needed.
While there are arguments for both sides, to ensure your motorcycle runs smoothly and trouble-free for a long time, performing a break-in period is a safe bet.
For the break-in period after purchasing a new motorcycle, aim for 1,000 km or one month, riding gently without putting sudden stress on the engine. Simply avoid "sudden" movements as you learned in driving school.
Even after the break-in period, avoid sudden accelerations and other high-load driving, and gradually increase engine RPMs.

How much does it cost? Where can it be done?

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Oil changes can be performed at motorcycle dealerships, motorcycle parts stores, and gas stations. Some car repair shops also perform motorcycle oil changes.
The cost for requesting an oil change is usually the oil price + 1,000 to 1,500 yen.
An oil change alone takes about 15 to 20 minutes, but there might be waiting times on holidays or before long vacations.

Cost of changing oil yourself

If you change the oil yourself instead of hiring a professional, you only pay for the oil.
The cost of oil is the same whether you have a professional do it or do it yourself, but doing it yourself will save you labor costs.
The cost of oil varies by oil capacity, and by displacement, it's roughly as follows:
• 50cc to 125cc: approximately 1,500 to 2,500 yen
• 250cc to 400cc: approximately 1,500 to 5,000 yen
• 400cc and above: approximately 3,000 to 6,000 yen
• Filter replacement: Oil change + approximately 1,000 to 1,500 yen
Additionally, you may need tools for oil change, an oil drain pan, and a motorcycle stand depending on the bike.

Tools needed for oil change

The tools required for an oil change are as follows:
• New oil
• Oil jug
• Drain washer
• Rag
• Rubber gloves
• Waste oil disposal box
• Tool for removing drain bolt (socket, box wrench, etc.)
An oil jug is used to pour new oil after draining the old oil.
A drain washer is a part that prevents oil leaks by being placed between the drain bolt and the engine.
A rag is useful for wiping up spilled oil or wrapping around the oil filler opening to prevent oil from getting on the engine during refilling.
The tool for removing the drain bolt varies depending on the location and size of the drain bolt on your motorcycle, but most motorcycles can have their drain bolt removed with a box wrench or socket wrench.
Additionally, for a filter change, you will need a new filter and a filter wrench in addition to these tools.

How to change motorcycle oil: procedure explained!

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Changing motorcycle oil follows these steps:
1. Prepare the necessary tools and new oil for the oil change.
2. Lightly warm up the engine (be careful not to overheat).
3. Remove the drain bolt and drain the old oil.
4. Once the oil has completely drained, tighten the drain bolt.
5. Pour in new oil (to the specified amount).
6. Start the engine, warm it up gently, and check for oil leaks.
Let's look at each step in detail.

1. Prepare the necessary tools and new oil for the oil change.

First, prepare the necessary tools and new oil for the oil change.

2. Warm up the engine lightly.

Warm up the engine lightly before draining the oil.
Cold oil has high viscosity and flows poorly.
Warming up the engine slightly lowers the oil's viscosity, making it easier to drain.
However, if the engine is overheated, the oil will become hot, and there is a risk of burns if it gets on your hand, so only warm the engine for about 30 seconds to 1 minute.

3. Remove the drain bolt and drain the old oil.

After lightly warming up the engine, place a waste oil box or drain pan under the drain bolt, then remove the drain bolt to drain the old oil.
The drain bolt tends to fall into the waste oil receiver as it loosens due to the oil pressure at the moment it comes off, so after loosening it to some extent with a tool, gently turn it by hand until it's fully removed.
If the engine is too hot, there's a risk of burns from the oil that comes out immediately after removing the drain bolt, so be careful not to overheat the engine.
If the drain bolt is too hot to touch, the oil is also hot, so wait a bit for the oil to cool down before removing the drain bolt.

4. Once the oil has completely drained, tighten the drain bolt.

Once the old oil has completely drained, tighten the drain bolt. At this time, replace it with a new drain washer.
Initially, tighten the drain bolt by hand, making sure it goes in straight.
If it's not straight, in the worst case, the screw hole could be damaged, or the bolt could break when tightened with a tool, so ensure it's straight before tightening.
Overtightening the drain bolt can also cause it to break, so be careful not to overtighten.

5. Inject new oil

After tightening the drain bolt, add new oil.
The oil quantity is fixed; neither too much nor too little is good, so add the specified amount.
The specified oil quantity is listed in your motorcycle's owner's manual or service manual.

6. Start the engine, warm it up gently, and check for oil leaks.

After adding the specified amount of oil, without starting the engine,
gently warm up the engine and check for any oil leaks.
If there are no leaks, the oil change is complete.

How to dispose of it? Disposal methods?

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Old motorcycle oil (waste oil) that has been changed cannot be disposed of as ordinary trash.
However, some municipalities allow it to be disposed of as burnable waste if it is solidified with a hardening agent or absorbed into paper or cloth (if it is not in liquid form), so it is advisable to check your local municipality's website.
If it cannot be disposed of as burnable waste, you will need to process the waste oil yourself.
Waste oil can be collected by the store where you purchased the oil or by a collection company, and some gas stations also accept it, so it's worth inquiring.

Is mixing (blending) engine oils of different viscosities OK or NOT OK?

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While there are no particular issues with mixing engine oils, it is not highly recommended.
What happens if you mix oils with different viscosities, grades, and base oils?

Mixing oils with different viscosities

There are no particular issues with mixing oils of different viscosities, such as "5W-40" and "15W-30," but it is not recommended.
Even for oils of the same brand and grade, the additives used may differ depending on the viscosity.
Especially for multi-grade oils, which must maintain an oil film across a wide range of temperatures from low to high, mixing them can lead to problems with the oil film characteristics.
Therefore, it is best not to blend oils except in emergencies, such as when you have drained the oil during an oil change and don't have enough new oil to refill it without blending.

Mixing oils of different grades

Although it is said that there are no problems with mixing oils of different grades, there is a possibility that the performance intended by the manufacturer may not be achieved.
It is best to limit blending to emergencies only and consider shortening the next oil change interval.

Mixing oils with different base oils

While mixing base oils is generally not considered problematic, differences in oil properties can lead to issues with the oil's sealing ability, potentially causing oil leaks.
Again, this should only be done in emergencies, and the next oil change interval should be shortened.
In general, blending oils is not highly recommended. Keep in mind that unexpected problems can arise, listen for any abnormal noises while driving, and if you feel any discomfort, change the oil immediately.

What happens if you overfill a motorcycle's engine oil?

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What happens if you exceed the specified oil amount during an oil change and overfill?
Here, we will explain the possible effects of overfilling oil and how to deal with them.

Effects and symptoms of overfilling engine oil

If engine oil is overfilled, various symptoms may occur, such as oil leaks, poor clutch engagement, unstable idling, and sluggish engine revving.

Poor clutch engagement

Engine oil also plays a role in reducing clutch friction, so overfilling the oil increases clutch resistance and can lead to poor engagement.

Causes various other malfunctions

In addition to poor clutch engagement, overfilling oil can cause the following symptoms:
• Oil leaks
• Decreased fuel efficiency
• Unstable idling
• White smoke from burning engine oil
• Air cleaner gets dirty easily
• Increased blow-by gas
While these symptoms can occur, the most common immediate symptom is oil leakage.

How to deal with and prevent overfilling

While it's not necessary to have the oil level exactly at the specified amount, if you've clearly overfilled, the best course of action is to drain the excess.
There are two methods for draining oil: draining from the top and draining from the bottom.

Top draining procedure

The procedure for draining oil from the top is as follows:
1. Warm up the engine.
2. Open the oil filler port and drain the oil using a syringe or oil changer.
3. Close the oil filler port, wait a short while, and then check the oil level with the dipstick.
You will need to prepare a syringe or similar tool, but this method is recommended as it allows for easy adjustment of the amount to be drained.

Bottom draining procedure

When draining oil from the bottom, the procedure is essentially the same as an oil change.
Warm the engine slightly, then remove the drain bolt to drain the oil. However, if the oil comes out too quickly, you might end up with insufficient oil.
You need to remove the drain bolt and quickly put it back on, so rubber gloves are essential to keep your hands from getting dirty with oil.
Top draining is more reliable for draining oil because it allows for easier adjustment of the amount to be extracted.

【For 4-stroke motorcycles】 7 Recommended Engine Oils!

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Here are some recommended engine oils for motorcycles, divided into 4-stroke and 2-stroke categories.
We hope this helps you choose the right oil.

1. Recommended 4-stroke oil: Honda Genuine Ultra G1

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Honda Genuine Ultra G1 is an oil designed for 50cc to 125cc mopeds and small vehicles.
With a viscosity of 10W-30, it boasts excellent fuel efficiency, and its mineral oil base makes it ideal for those looking to save on oil costs.
This oil is specifically developed for Honda motorcycles, making it a must-have for Honda owners. The Honda Genuine seal also offers peace of mind.

2. Recommended 4-stroke oil: Castrol POWER1

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Castrol POWER1 is a popular oil used by many.
It specializes in acceleration performance and offers good throttle response, making it recommended for those who want to ride their bikes smoothly.
The base oil is semi-synthetic, suitable for everything from commuting to touring.

3. Recommended 4-stroke oil: Yamaha Genuine Premium Synthetic

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Yamalube Sports is a Yamaha genuine oil that offers an excellent balance of price and performance.
It is a semi-synthetic MA2 standard oil that can be used regardless of displacement or vehicle type, making it suitable for a wide range of motorcycle scenarios, from commuting to touring.

4. Recommended 4-stroke oil: Honda Genuine Ultra E1

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Honda Ultra E1 is a standard oil for 4-stroke scooters.
It is a mineral oil with MB specifications, but it firmly covers the necessary performance for scooters, making it recommended for those who want to keep oil costs low. It also offers the peace of mind of genuine Honda products.
Since E1 is an oil for scooters, using it in MT (manual) vehicles can cause problems. If you're looking for genuine Honda oil for an MT, G1, introduced in point 1, is recommended.

5. Recommended 4-stroke oil: Verity MA 4-stroke specific engine oil

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• Compatible with older and large-displacement vehicles.
• High viscosity prevents compression leaks, making it ideal for older, large-displacement 4-stroke motorcycles.
• Maintains a thick oil film during summer traffic jams, protecting the engine.
• Mineral oil, so oil leaks are less likely in older vehicles.

6. Recommended 4-stroke oil: Castrol GO!

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Castrol GO! is an oil with excellent engine cleaning properties.
Its anti-wear special additives and oxidation stability keep the engine consistently clean.
It supports a wide range of scenarios from commuting to long-distance touring and tandem riding, and is recommended for those who want a light and responsive ride with good throttle response.

7. Recommended 4-stroke oil: Yamaha Genuine Yamalube RS4GP

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Yamaha Genuine Yamalube RS4GP is Yamaha's top-tier oil, developed using expertise from racing.
Leveraging experience and knowledge gained from the pinnacle of motorcycle racing, MotoGP, it is fed back to the commercial level, offering high performance that easily handles intense sports riding with prolonged high RPMs.
This is a high-performance oil suitable for high-performance engine bikes like SS models.

【For 2-stroke motorcycles】 5 Recommended Engine Oils!

Here are 5 recommended oils to help 2-stroke owners choose the right one.
Some oils have similar designs to 4-stroke oils, so please ensure it is a 2-stroke oil before purchasing.

1. Recommended 2-stroke oil: Honda Genuine Ultra S9 10W-40 1L

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Honda Genuine Ultra pursues further environmental performance and high quality.
The engine runs smoothly, making it recommended for those who seek a smooth ride. It's an environmentally friendly Honda Genuine oil that also suppresses white smoke emissions.
For 600cc class and above / 400cc class / 250cc class

2. Recommended 2-stroke oil: Yamaha Genuine Yamalube Mini Scooter

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Formulated with friction modifiers to reduce friction loss. This 4-stroke mini-scooter specific oil is designed to improve starting, idle stability, and acceleration performance in small displacement vehicles.
Note: This is an oil specifically for 4-stroke scooters. Using it in other vehicles may affect clutch performance, so please be careful.

3. Recommended 2-stroke oil: Motorex Cross Power

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Optimized for 4-stroke off-road vehicles with the latest technology.
This oil is suitable for off-road use under severe conditions such as racing. Viscosity changes are less likely, allowing for continuous use at high temperatures.

4. Recommended 2-stroke oil: Motorex Cross Power 2-stroke 1L

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• Oil developed for off-road vehicles.
• 100% synthetic oil developed for off-road vehicles with frequent throttle opening and closing. Can be used for both separate and pre-mix lubrication. Recommended mixing ratio is up to 100:1.

5. Recommended 2-stroke oil: Castrol POWER1 2T

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Castrol POWER1 2T is an oil with excellent acceleration performance.
It provides smooth acceleration from low to high speeds and achieves excellent quietness at all RPM ranges.
This oil supports smooth and powerful riding, from city cruising to high-speed touring.