Vol.1
Oil and Mechanical Components Developed Simultaneously

Why It’s Called a “Liquid Engine Component”

Visually, oil for motorcycles and oil for cars don’t look very different, but a major distinction between the two is that motorcycle oil must fulfill a greater number of roles. Car engine oil primarily serves to lubricate and seal the engine, and parts like the transmission and differential are separate and have their own lubrication systems. But as motorcycle engines must be smaller out of necessity, the clutch and transmission are designed as a single unit with the engine, meaning that a single type of oil has to cover the functions for all of them.

The engine needs things like lubrication, sealing, cooling, cleaning and rust prevention; the clutch needs the right amount of viscosity to work well; the transmission needs a buffer to cushion the impact of the gears meshing. In other words, each requires the oil to do something different. In normal running conditions, the oil makes a full circulation of the engine in a little less than 10 seconds and performs many functions in that time.

But Yamaha’s engines are not limited to only motorcycles and are found in machines often used in very specific environments, like outboard motors, snowmobiles and ATVs. Just as engine components and mechanisms are developed and optimized for the rigors of hard use and tough environments, the oil is also developed alongside the engine it will be used in. This is the reason oil is considered a liquid engine component by Yamaha.

The History of Genuine Yamaha Oil Development

There is one piece of technology that symbolizes Yamaha’s history of developing its oil and mechanical parts alongside each other – the “Autolube” pump. Developed in 1963, it was the first device of its kind in the world. At the time, 2-stroke engines used oil mixed into gasoline ahead of time according to the correct oil-to-gasoline ratios for lubrication. However, with the creation of the Autolube pump, all that was needed was to put the oil into a separate oil tank, doing away with the need for pre-mixing the oil with the fuel for lubrication. The convenience this brought was praised by riders the world over.

But those weren’t the only benefits of a separate system for oil lubrication. Designing the Autolube pump to work in conjunction with the throttle wire made it possible to inject oil into the gasoline at the right mixture ratios for however the engine was running. This not only allowed the engine to perform at its best, but also contributed to reducing the amount of white smoke emitted from the exhaust as well as reducing the amount of oil deposits stuck to the muffler.

The Autolube pump was fitted with a plunger pump.

The Autolube pump had a simple structure.

The catalyst for developing the Autolube system was a racebike for the Road Racing World Championship Grand Prix. Yamaha began participating full-time in GPs in 1961 at the Grand Prix of France, but had actually already been entering other races with machines equipped with separate automatic oil injection systems and had been gathering data. Yamaha’s engineers for production models took a hint from the forced oil lubrication pump being used on Yamaha GP machines of the time to develop the Autolube system using a plunger pump. The YA-6 released in 1964 became the first production motorcycle to feature an Autolube system.

The 250cc racebike that contested the Suzuka round of the 1962 All Japan Road Race Championship was fitted with the automatic lubrication pump.

The YA-6 was the first production model to adopt the Autolube system.

While the system was being developed, another effort was underway to produce an oil that would help the Autolube system function more efficiently. To ensure strong oil film retention, a low degree of combustion residue, good detergency, good fluidity at low temperatures and more, Yamaha began testing 2-stroke engine oil available on the market at the time along with experimental oils from petroleum refineries. The goal was to evaluate their capacity for preventing engine seizure, inhibiting wear and friction, carbon residue build-up, clogging of the exhaust ports, their effects on the piston rings, burden on the spark plugs and more. The process included both bench tests in the workshop and real-world tests on the road, and the result was the system-specific Yamaha Autolube Oil. The work from this time thus became the starting point for future development of Genuine Yamaha oil.

Chapter 1: The History of Genuine Yamaha Oil

Vol.2
Homemade Blends

An Engine Tester Creates Genuine Yamaha Oil

At Yamaha, the engineers constantly working on the mechanical aspects of the engine are the ones that formulate the oil it will eventually use. This approach started in the 1970s, when Yamaha products began being exported to numerous overseas markets, the number of model variations in the lineup was growing, and engines were steadily achieving higher and higher performance.

In the midst of this, it became a pressing matter to create Yamaha-brand engine oils with an eye on what the future held for the industry as well as allowing customers to enjoy their motorcycling lifestyles with greater peace of mind. At the time, there were no uniform company standards for evaluating engine oil and the main method for evaluation was running the engines on a test bench. It was laborious and time-consuming work. It was around that time that a newly hired engineer was assigned to Yamaha’s Engine Testing Group — Yoshinobu Yashiro.

Employees involved in engine development generally come from mechanical engineering backgrounds, but Yashiro was a somewhat atypical hire as he specialized in chemical engineering. Soon after joining the company, his superiors told him, “Since you’re a chemistry guy, make sure you also take a good look at the oil.” So alongside his regular engine development work, he began research into engine oil on his own. Analyzing the oil on a molecular level to determine its makeup certainly was the right territory for a chemist.

Yashiro’s first task was to put the 2-stroke 125cc engine of the A7 on the test bench and use it to analyze the engine oil commonly used at the time. But the focus of this exercise was not only on the oil itself. If a problem occurred with the engine, it was not always clear whether the cause was the oil or the engine components themselves. If that could be properly identified, it would lead to more precise engine and oil development. Yashiro also conducted experiments by altering the piston and cylinder specifications and checking the results. This was in order to make proper observations about everything involved as an engine development engineer.

He then moved on to experiments and analysis using gas chromatography. This method vaporizes the oil, turning it into gas form. The components within the gas are then separated, allowing one to measure their individual density and thus understand the makeup of the oil. Yashiro would add one drop of oil to the gas chromatograph and come back to check the result during lunch or a short break before adding another drop of oil. Keeping up this rather tedious work is what enabled him to see what the oil was really made of. However, the results that emerged were not what he was aiming for.

After trying several kinds of methods for analyzing oil, Yashiro finally arrived at thermal analysis. By using a thermal analyzer, you can determine the oil’s composition by examining its response to heat. By verifying the components of the oil and their molecular weights based on the amount of energy, etc., released during oxidation, it became possible to approximate the properties of the base oil and its additives.

This in turn made it possible to express the oil’s basic performance with numbers. Cross-referencing that with the engine performance they were looking for, Yashiro could get a general idea of what class of base oil and what blend of additives would likely work best. Once it was possible to make conjectures in this way, Yamaha’s path to more efficient oil development was opened.

The 1968 A7’s engine was used in the experiments to develop Genuine Yamaha oil.

The Birth of Autolube Super

As a chemical engineer, Yashiro desperately wanted to know the makeup of the oils he was studying, but at the time, oil manufacturers did not disclose that information. It was like there was an invisible wall between oil manufacturers and motorcycle manufacturers formed by an underlying doubt that neither could understand the other on a professional level. But there is an interesting story behind how this wall eventually came down.

Now able to call on his own knowledge and information from his extensive studies about oil composition and how oil worked in an engine, Yashiro acquired a base oil and additives to work with. He then blended them himself into an experimental oil that met his performance requirements. He put four liters of it into a can and hand-delivered it to the oil manufacturer along with a paper clearly describing its composition and effects. His request was simple: “Please produce an oil that surpasses this one.”

With 2-stroke engines, oil goes from the oil tank to the oil pump, is mixed with gasoline and then enters the combustion chamber. Having lubricated the engine, it exits out of the exhaust pipe along with exhaust gases. Without knowing the ins-and-outs of how the engine works and an understanding of things like piston seizure, ring scuffing, exhaust smoke, intake port and exhaust blockage, and starting the engine in cold conditions, it is impossible to develop a good engine oil.

Thanks to his knowledge and expertise about engines as well as oil, Yashiro was able to create his own blend of engine oil. After it became clear to the oil manufacturers that Yamaha understood oil well, they eventually began to disclose data about the composition of their oils and more, and Yamaha engine development grew in both precision and efficiency.

The oil that came about from this story was Autolube Super, and it won long-lasting praise from the market. Its wide range of compatibility meant it could be used in anything from scooters to supersport motorcycles, and it had the added benefits of reducing exhaust smoke and bringing better engine starts in cold weather. Autolube Super later evolved into its R and RS versions, and is still on sale today.

It could be said that the know-how that has been passed down to the current day for evaluating Genuine Yamaha oil was brought about by the development of Autolube Super. First, assess an oil’s composition and then quantify and evaluate its performance as a Genuine Yamaha oil across aspects like viscosity and vaporizability, its ability to reduce friction, its shear stability and susceptibility to foaming. Doing this not only enabled more efficient oil development but also carried the process over from motorcycles to developing Yamaha oil for outboard motors, snowmobiles, ATVs and other products. As a liquid engine component, Yamaha engine oils are the way to bring out 100% of a Yamaha engine’s performance.

Autolube Super and Autolube Super RS
are still on sale today.

Vol. 3
Creating Oil for the VMAX with an XS250 Engine

The Road to Genuine Yamaha 4-Stroke Oil

Yamaha’s specialty had long been 2-stroke sport bikes, but with the launch of the XS-1 in 1970, Yamaha began to introduce 4-stroke models one after another. However, in the decade between then and 1980s, there still was no company standard for evaluating Yamaha motor oil, so just as it had been with 2-stroke oils, discussion began to regularly take place regarding the development of Yamaha 4-stroke oil. The first thing the engine development teams did was closely analyze the 4-stroke car engine oils available on the market to try to decide what type would be best suited to Yamaha machines.

Around that time, Yamaha oil legend Yoshinobu Yashiro (introduced in Vol. 1 and Vol. 2) had his hands completely full between developing 2-stroke engines as well as Genuine Yamaha oil. It was then that Tohru Miura, another engineer with a chemistry background, was assigned to the Engine Testing Group. He himself had requested engine development duties: “I’m tired of chemistry; I want to work on the machines.”

Having somebody like Miura join the team must have been a godsend to the extremely busy Yashiro. Miura, like Yashiro, was given the job of primarily working on engine development but also conducting research into oil on the side. Yamaha does not have engineers solely devoted to oil work. To achieve excellent product reliability as well as boost performance, engineers that understand engines and oil with the same levels of expertise are needed.

What Yamaha placed particular importance on when developing its own 4-stroke motor oil was testing with real engines and machines. After all, you can’t fully understand oil without running it through the engine first—that’s how Yamaha approaches oil development.

At the time, Miura was involved with developing the engine for the first-generation VMAX. As Yamaha was quickly moving towards sport bikes with more engine displacement and higher power like with the VMAX, he was trying determine what kind of engine oil would best fit such motorcycles. Since there was no way—and no time—to run an oil test on an engine still under development, Miura’s solution was to use an XS250 engine on a test bench. Could an air-cooled 250cc twin engine really take the place of a 1,200cc V4 DOHC engine—with V-Boost, no less—for testing?

The XS250’s engine was used for oil testing.

A pamphlet for the air-cooled XS250 when it was released

The 1,200cc VMAX was a bike exemplifying the 1980s.

The VMAX’s liquid-cooled V4 was the world’s most powerful production motorcycle engine when it was built

As a matter of fact, air-cooled, small-displacement engines are actually very hard on oil. The ultimate goal of engine oil is to prevent the engine from breaking, so Miura wrung the engine out to its absolute limit while examining in great detail the oil’s performance, such as lubrication, cooling properties, detergency and the presence of any air bubbles, as well as things like the condition of the metal around the camshaft and crankshaft bearings. In this way, Miura took advantage of the expertise gained in the 2-stroke era and built on it with further R&D, later resulting in today’s Yamalube.

Boosting Performance with Oil

Today, Yamaha products are run on the land, in the water and in the air in areas all over the world. The quality standards for Yamalube—the Genuine Yamaha oil used in everything from motorcycles and outboard motors to snowmobiles and ATVs—were established in the 1980s. To match the rapid progress being made in engine technology at the time, Yamaha engaged in a variety of efforts to try and innovate with motor oil as well.

The standard choice for Yamaha motorcycle engine oil today in Japan is Yamalube Sports, but its origins can be traced back to Yamalube Extra Z, an oil developed in the early part of the 1980s. In the history of Genuine Yamaha 4-stroke oil development, Extra Z was epoch-making in its significance. It all began with an encounter with a base oil created by one oil company. The molecular makeup of the mineral oil had been chemically altered with a method called hydrotreatment. While it was still a mineral oil, it had viscosity characteristics on par with today’s semi-synthetic oils—a revolutionary achievement.

When Miura got word of this, he quickly set up a meeting with the oil producer and requested that they employ the method to produce a Genuine Yamaha oil. The request was accepted and this eventually led to the development of Yamalube Extra Z. Incidentally, Yamaha was among the earliest motorcycle manufacturers to commercialize an engine oil made with hydrotreatment.

The main job of engine oil is to keep the engine from breaking down, but Yamaha did not stop there. How much more performance can we get from oil alone? In essence, Yamaha began to view oil in the same way as designing an engine part or mechanism.

In 1985, the FZ250 Phazer debuted with a 4-cylinder engine that could rev up to 16,000 rpm and it quickly grabbed the market’s attention. The design precision and sophistication of the engine was impressive, but so also was the challenge to see if more horsepower could be extracted with oil. The engine development team carried out tests using molybdenum as an additive.

Yamalube Sports inherits the performance-boosting qualities of Yamalube EFERO FX.

What Miura and his team set out to tackle next was to develop an oil with all the attributes ideal for a motorcycle. The project put worries about cost and expenses aside, allowing the engineers to do all they possibly could.

From their firm determination and hard work came Yamalube EFERO R, a full-synthetic oil with a low, 5W-20 viscosity. Its performance was on par with full-on racing oil and the model the team had in mind was the FZR750R, a race homologation model also known as the OW01. During the height of the boom in racebike replicas in Japan, EFERO R eventually evolved into Yamalube EFERO RS, a blend of oil also usable in production racing.

The FZR250 Phazer’s engine could rev to 16,000 rpm, something that won it much attention.

Molybdenum is so effective at reducing friction resistance that just adding it to the oil raises the idle rpm of the engine. But if friction resistance is reduced too much, it can result in side effects like clutch slippage. So, the team optimized the blend of the additives while coming up with creative solutions for the engine parts and mechanisms to deal with such effects. The oil that came about as a result was Yamalube EFERO FX.

The FZR750R (OW01) was designed and engineered to meet technical requirements in order to be used as a racebike, i.e., race homologation.

However, as much as the FZR Series models were referred to as replicas of racebikes, Yamaha was insistent while designing them that they also be friendly, easy-to-ride machines. In the same way, the oil needed to cover a broad spectrum of performance that included the average rider using their bike for everyday fun. All the expertise gained through these endeavors has been passed down to the Yamalube products in use today all around the world.

Chapter 2: High-Performance 4-Stroke Oil

Vol. 4
Harsher Use than a Racebike: Delivery Bikes in the Summer

Misunderstandings About Engine Oil

In interviewing Yoshinobu Yashiro, a legendary figure in the development of Yamaha engine oil, there was one moment when he showed a bit of lingering frustration. “Many people have misunderstandings about engine oils,” he said. “The prevailing idea is that you want a high-end oil for a supercar and a standard, run-of-the-mill oil for a 660cc Japanese kei compact car. But, which car do you think puts more stress on and demands more performance from the engine oil?”

A supercar’s big and powerful engine only needs to run at about 2,000 rpm to cruise at 100 km/h. On the other hand, a kei car has to maintain something around 6,000 rpm to do the same. “The same misunderstanding exists with motorcycles as well,” Yashiro continues. “Many think the oil for a supersport bike will be high-performing while the oil for a 50cc scooter won’t be.”

Yashiro explains that oils for supersport models are indeed specifically blended with a carefully formulated mix of additives aimed at boosting performance. However, he then asks, “What kind of bike do you think places the toughest demands on engine oil?”

His answer wasn’t what most people would expect: “It’s the small bikes post offices use for delivering the mail or the ones insurance salespeople use for making their rounds in the midsummer heat. Because they have little power, the throttle is kept fully open most of the time once they get going, and sometimes they are kept idling as the rider talks at length with a customer. The heat is scorching under the summer sun and there is no wind, not to mention it’s an air-cooled engine! Nothing is tougher on oil than these kinds of conditions.”

The Yamaha Town Mate was built to withstand the toughest of use conditions.

The Gear’s liquid-cooled engine reduces the demands on its engine oil.

Of course, a supersport model being run at full tilt during a trackday or in production racing presents some very tough conditions for oil, but these machines are typically liquid-cooled and fitted with other parts to keep temperatures in check like an oil cooler and piston cooling system. This keeps cylinder temperatures at around 140 °C.

In contrast, the cylinder temperature with small-displacement air-cooled engines can reach to 230–240 °C and oil temperature can exceed 120 °C, which means from the oil’s standpoint, a supersport bike is a much more welcome environment. Also, the engines in outboard motors place equally stringent demands on the oil. Once out on the water, the engine is often kept running at full throttle for hours on end, and the smaller the engine’s displacement, the tougher things become for the oil.

Small-displacement outboard motors are exposed to incredibly harsh use environments.

From the company’s earliest years, Yamaha Motor devoted itself to developing Genuine Yamaha engine oil for its small-displacement, high-output 2-stroke engines. One of the first challenges engineers had to tackle was how to use oil to further prevent piston seizures. The lesson they learned was to use the best possible base oil.

With today’s Yamalube oils, the level of quality is essentially the same for our supersport and 50cc bike oils; the difference lies in the “tuning” of each oil to fit the model’s intended use. In emphatic terms, putting a standard-class Yamalube oil in a YZF-R1 will not cause any particular trouble. However, if you want to bring out the full potential of the machine, a high-performance oil like our RS4GP is the best choice.

This is because our Yamalube oils are “liquid engine components” designed specifically with the individual product’s performance and uses in mind.

The highest grade of Yamalube oil available: RS4GP

Oil Myths

Today, there are all kinds of high-end, high-performance engine oils on the market that leverage the full resources of their respective oil companies. It is also only natural for riders to want an oil that adds to their machine’s performance—it’s one of the joys of being a motorcyclist, after all.

However, an expensive oil doesn’t always mean it’s the best oil. From the standpoint of an engine builder, nothing is better than an oil that brings out the full performance potential of the final machine.

The YZF-R1’s engine was designed to take maximum advantage of the oil it uses.

Yamaha strongly recommends using Yamalube oils for Yamaha products. Because they are all created by the very engineers designing the engines, we believe these oils offer the best compatibility with the engine’s various parts and mechanisms. In fact, Yamaha’s engine development process itself begins with selecting a “development oil” created according to our special standards, and then the engine’s specifications are decided.

If choosing this development oil marks the start of creating the oil for the engine, the finish line is evaluation and approval as a Genuine Yamaha oil by the Oil SIG (Special Interest Group) at Yamaha Motor headquarters.

All Genuine Yamaha oils manufactured around the world today meet the high standards set by Yamaha headquarters, but the final decision of whether or not they can be sold under the Yamalube brand name is made by the Oil SIG. As a company developing and manufacturing a diverse portfolio of products for the world’s markets—from motorcycles and outboard motors to snowmobiles, ATVs and portable generators—how does Yamaha certify an oil as being suitable for a specific product?

It simply isn’t feasible to assess every submitted oil with an engine test bench. Instead, what comes into play is the vast stock of data accumulated over decades of in-house oil development. With this data, today’s Oil SIG is able to gauge everything about the oil and make evaluations from the technical documents compiling information like the type of base oil, the additives used and the blend ratios.

All of the Yamalube oils sold in Japan (motorcycle oils shown) are also evaluated and approved by Yamaha’s Oil SIG.

“It isn’t a product if it isn’t world class.” These are the often-spoken words of Yamaha Motor’s founding president, Genichi Kawakami, and they are a guiding principle behind what makes Yamaha products found all over the world inextricably linked to the good reputation Yamaha enjoys today. Though seldom seen, Yamalube oil is hard at work within each and every one of those engines, helping them bring users the best possible performance.

Vol. 5
Oil is a Discipline of Chemistry

Yamaha Has No Oil Development Division

Where exactly does Yamaha develop Yamalube oil? As mentioned earlier in this series of articles, Yamaha does not have a department specifically devoted to oil development. From the 1960s when the Autolube pump and Autolube oil was developed to the present day, the engineers in charge of engine testing have carried out oil development alongside their main engine development duties. However, what is somewhat unique is the fact that these engineers’ backgrounds are not in mechanical engineering, but chemical engineering. It’s impossible to understand engine oil and its requirements without understanding the mechanisms of the machine itself, and it’s vital to be able to imagine the oil as it fills the countless gaps between the respective mechanisms of the engine, clutch and transmission while they operate at incredible speeds.

There are largely two types of lubrication: fluid film (hydrodynamic) lubrication and boundary lubrication. With cars, the engine, clutch and transmission are separate from each other, and each requires its own specific oil. But in motorcycles, those are all connected as one unit, so a single oil must lubricate everything. For example, while the pistons and cylinders rely on fluid film lubrication and the type of base oil is key, transmission gear engagement relies on boundary lubrication, so the blend of oil additives is key. Then, there is elasto-hydrodynamic lubrication for the cam and camshafts...and so on.

So, the oil characteristics needed for each mechanism of the power unit differ. As such, if engineers with intimate knowledge of (1) how an engine part moves, (2) the type of metal the part is made of and (3) the chemical properties of oil itself are the ones creating the oil for the engine, you could say that it’s the quickest shortcut to making progress.

The engine, clutch and transmission are all a single unit with a motorcycle engine (MT-09 engine pictured).

The inner walls of an engine cylinder and a piston use fluid film lubrication (YZ450F engine pictured).

A motorcycle transmission and its many gears use boundary lubrication.

Back in the 1970s when Yoshinobu Yashiro was working by himself on developing standards for Genuine Yamaha motor oil, he realized that oil manufacturers likely did not have enough knowledge and understanding of the finer workings of engines. But that was understandable; to a chemical engineer at an oil refinery, pistons and gears are a completely different world. That realization set Yashiro on the path to creating Yamaha’s own standards for motor oil. His approach was logical and straightforward: learn to understand what I don’t understand already. His path up this proverbial mountain had two different starting points—mechanical and chemical—but the goal that lay at the summit was the same.

Intriguing Because Both the Mechanisms and the Oil are Unknowns

Yamalube is created by engineers who understand both machinery and chemistry. The path that Yoshinobu Yashiro and Tohru Miura paved is now in the hands of a new generation. Another group of new engineers with chemical engineering backgrounds has joined Yamaha’s Engine Development Division. “The reason Yamaha doesn’t have an oil development division is that if we did, everybody would look at things primarily from an oil development perspective,” says Miura. “We create engines, not motor oil, so our job is to figure out the best oil for the engines we make.”

We tend to think that with all the progress made in the many fields of science and technology, anything and everything in the world is understandable with analysis. However, Yamaha believes that real technological progress is found in the areas where this is not the case. In the past, oil was not well understood. Until the 1960s, the oil selected by a handful of experts was considered good oil, and their educated guesses produced positive results again and again. However, those oils were chosen with qualitative research, so carrying over those advances to other product categories was no easy task.

Yashiro analyzed everything related to oil and the engine, and quantified his findings. This opened the path for developing Genuine Yamaha motor oil, but things didn’t end there. In the 1980s at the Small Engine Technology Conference (SETC) held in Melbourne, Australia, Yashiro presented a paper on the relationship between engines and oil using thermal analysis, and the results of the paper were widely shared throughout the engineering community. Yashiro stated that the reason he did it was because nobody was interested in the topic at the time, but one could say it was to spread to a wider audience the roles that oil has in improving engine reliability.

In Japan, the “MA” and “MB” markings seen on motor oil indicate the standards it meets and are from the Japanese Automobile Standard Organization (JASO). These motorcycle oil standards were established in 1994 and are unique to the Japanese market. Though Japan was already a global leader in motorcycle manufacture and export then, there were still no standards for motorcycle oil quality or a defined method for testing them. Until they were created, the standards used included those from the American Petroleum Industry (API), the International Lubricant Standardization and Approval Committee (ILSAC) and the Association of Constructors of European Automobiles (ACEA), but all of these were based on motor oils for cars.

Since motorcycles have the engine, clutch and transmission all as a single unit, there was a need to create standards specifically for them, and Japan’s four major motorcycle manufacturers got together and laid out these standards. At the time, car motor oils were starting to include special additives designed to improve fuel economy, but these could actually cause problems when brought over to motorcycles.

Yamaha took on a very proactive role in creating the JASO standards for motorcycle oils, contributing information like its oil testing methodology and evaluation criteria—core components for establishing such standards. Although the manufacturers involved were all competing with each other, everyone’s goal was the same: create an environment in which motorcycles can be enjoyed with greater peace of mind by improving reliability, lessening the impact on the environment and more. However, standards being put in place does not necessarily mean that all oil is created equal.

Yamalube is a liquid engine component. As this component plays an essential role in improving the reliability of Yamaha products the world over—be it on the land, water or snow—we continue to carry out independent R&D to stay in stride with the constantly higher-performing mechanisms and technologies of today. With technology, there is no “finish line.” In our quest to find new uses and to create new value for our customers, there will only be more and more things that we don’t yet understand. But at Yamaha, breaking through and making those unknowns our expertise is who we are.

The JASO MA2 engine oil standards listed

Vol. 6
Keeping Real-World Use at the Forefront

For Unrivaled Reliability: Genuine Yamaha Oil for Marine Engines

With marine engines and engines used on land, there are naturally major differences in how they are used. As marine engines are for use on the water, rust prevention is one obvious concern, but the biggest is the load these engines are subjected to; it is common practice to run marine engines at full throttle for hours on end. From large fishing boats out to catch marlin to tiny skiffs equipped with a single sub-10 horsepower outboard motor, the uses and environments marine engines are exposed to are severe.

Since releasing the 2-stroke P-7 outboard motor in 1960, Yamaha outboards found use not just in sport fishing, but also in commercial fishing worldwide, and the number of owners quickly grew. As this happened, the role of engine oil became an even greater point of focus when working to improve engine reliability. In the 1980s, Yamaha began equipping its outboards with Autolube pumps, which had won a strong reputation for reliability in the motorcycle industry. The Autolube system always delivered the right amount of oil to mix with the fuel, and since fuel quality would vary greatly by market region, this mechanism not only protected the engine but also extracted maximum performance from the oil itself. However, the norm at the time was to use whatever oil was locally available for sale in each country, and the concept of oil created and approved by the manufacturer of the outboard did not yet exist.

The P-7 was Yamaha’s first outboard and its engine was based on the YA-1 motorcycle engine.

It was around then that Yamaha engineer Takao Nagai was assigned a key role in developing marine engines. For 30-odd years and even to this day, he has been developing both marine engines and Genuine Yamaha oil. There was one particular incident during his career that led to his decision to pursue creating Yamaha-brand oil for marine engines. In the late 1980s, there were several customer complaints about the pistons in large-displacement, high-power outboard engines. Furthermore, this wasn’t limited to Yamaha; other manufacturers were facing similar issues with their outboards.

The engine development team had a hypothesis: “It seems like this isn’t only a mechanical issue. What if the engine oil is also playing a part in this?” To test it, they gathered together several leading marine engine oils available on the market and ran repeated tests with actual engines. Just as had been suspected, the testing results showed that oil was one of the causes of the piston issues. In those days, the TC-W2^® oil standard for North America put in place by the National Marine Manufacturers Association (NMMA) was the de-facto guideline for evaluating fuel economy and eco-friendliness, and each oil company sold oil meeting the standard. However, when outboards were subjected to continuous heavy loads during Yamaha’s tests, it became clear that the resulting rise in engine temperature could cause the piston rings to stick.

With this new knowledge, Yamaha set to work on developing a Genuine Yamaha oil for outboard motors as quickly as possible. Running outboards at full throttle for long periods of time and stressing the engine was not something limited to large-displacement models. If anything, smaller outboards would be even more drastically affected because of the heavy workload they are often subjected to. Yamaha’s oil not only satisfied the TC-W2^® standards and the following TC-W3^® standards, but the company went further and established even stricter in-house standards for itself. By researching additive blends containing cleaning agents and more, the team completed a Genuine Yamaha oil for marine engines.

Large-displacement V-engine outboards are what led to the development of Genuine Yamaha oil for marine engines.

Today, the performance of an oil can now be determined by simply examining its composition and other specifications based on the wealth of data compiled over the years. But before that was possible, extensive bench testing of actual engines was critical. In the past, test outboards would be set up in water tanks and run continuously at full throttle for an unimaginably long time. They were then disassembled and engineers would check both the condition of the engine’s internals and the state of the oil. This step used to be an irreplaceable part of the development process. With an engine always in its best condition, it can power the boat and its crew out of and back to port safely. Yamaha engineers have not just the engine itself, but the lives of the people who will rely on it in mind as they work.

Yamalube oil for 4-stroke marine engines

Genuine Yamaha 2-stroke outboard motor oil

Chapter 3: Developing Oil for Greater Reliability

Genuine Yamaha Snowmobile Oil Developed in -30°C Temperatures

Much like marine engines, the engines in snowmobiles are also directly connected to the lives of riders. Being haunted by engine trouble in the middle of a deserted snowfield in below-freezing temperatures is something nobody wants to think about, let alone experience.

The 2-stroke VK540V is a long-seller renowned for its reliability.

Yamaha developed the SL350 as its first snowmobile. It was powered by a 2-stroke 350cc 2-cylinder engine and was released on the North American market in 1968. Since snowmobiles are used in extremely cold climates, the oil they use requires special qualities and characteristics, among which is the ability to fire up the engine in cold temperatures. The majority of snowmobiles today have 4-stroke engines and electric starters, but 2-stroke engines have recoil starters that require the rider to pull a cord to turn the crank and start the engine.

Yamaha’s first snowmobile, the SL350

For example, what would happen if you put regular motorcycle engine oil into a snowmobile in -30°C temperatures? The oil in the engine would behave like olive oil put in a refrigerator, thickening and inhibiting the crank from turning. So, snowmobile engine oil needs to have low viscosity, but excellent fluidity at low temperatures comes at the cost of reduced lubrication performance. Since snowmobiles encounter a lot of resistance from the snow while underway, the throttle must be kept almost fully open for much of the time, subjecting the engine to heavy loads that can lead to engine seizure. But even if molybdenum is added to the oil to reduce frictional resistance, this causes the recoil starter’s one-way clutch to slip.

The engineer that worked to overcome these two conflicting qualities while developing Genuine Yamaha oil was Manabu Kai. As an engine test engineer since the 1980s to the present day, Kai has viewed engines and oil from a single, unchanging perspective over his long career. As part of Yamaha’s engine testing team, he regularly flew to Alaska in the middle of winter for two months of engine tests in the frigid cold. The team would rent a restaurant closed for the winter and set it up as their base camp. They slept there at night and rode snowmobiles in the surrounding fields during the day, carrying out real-world tests that couldn’t be recreated with bench testing. The battery of testing included engine starts, riding uphill and downhill, and over endless bumps in the trail. Kai checked and verified firsthand if the oil was doing its job properly throughout the testing, examining oil pumps, engine oil passages and more.

The method chosen for developing Genuine Yamaha oil for snowmobiles was to select a base oil from the data accumulated with motorcycles, and blending it with the appropriate additives. The standard for the oil’s evaluation would be the engine’s ability to start in cold temperatures—a point especially important with snowmobiles. When engines were tested in cold rooms at Yamaha Motor headquarters at -40°C temperatures, the recoil starter would often be too heavy to pull. Otherwise, the first successful pull would be heavy, and then on the second try, the cord would suddenly become light and the engine would start up. There was no logical explanation for the phenomenon, so it was through these field tests that the optimal base oil and additives were decided upon.

Yamalube Snow Oil R-FORCE yields outstanding engine starts in cold temperatures and excellent lubrication during high-load use.

In 2002, Yamaha succeeded in becoming the first company to transition to 4-stroke snowmobiles. At the time, the YZF-R1 flagship supersport motorcycle featured the latest motorcycle engine know-how for both fuel combustion and oil technology. With an engine based on the R1’s, the RX-1 4-stroke snowmobile made a sensational debut.

In 2002, the RX-1 set off Yamaha’s transition to 4-stroke snowmobiles.

There is a unique synergy with Yamaha’s products and its technologies. Motorcycle engines, marine engines and snowmobile engines are all used in different environments, and their respective specifications and performance requirements also differ. However, the know-how and technologies Yamaha builds up within one product category inevitably becomes woven into a different category. In the same way, our knowledge and expertise with engine oil accumulated over decades of R&D is immune to product boundaries and is shared throughout our businesses. Since the requests we make to oil companies contain performance requirements laid out by our engine development divisions, they supply us with high-quality oil meeting the strictest standards. Implementing that same method on a global scale is how we create Yamalube oil for every Yamaha product.

Chapter 4: Developing Oil for Tough Use