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JASO Explained Part 1: 4-Strokes


MotoTribology

JASO Explained PART 1:

JASO 4-Stroke Engine Oil Specification

       The Japanese Lubricating Oil Society or JALOS is the organization that regulates the performance of various motorcycle specific engine oil types. JALOS is the organization that regulates and oversees the implementation of the JASO motorcycle engine oil specifications. For motorbike applications, there are two separate JASO categories for 4-stroke and 2-stroke applications with numerous subdivisions within each category. For this article I am going to focus on explaining the 4-stroke category.

       Let’s begin with a quick background of the 4-stroke JASO specification. In 1998, JALOS organized the first widely accepted standard for evaluating performance of motorcycle engine lubricants. This was necessary due to an increasing number of automotive oils meeting the energy conserving and resource conserving specifications through the additive technology of friction modifiers. Because these friction modifiers are not designed for compatibility of wet clutches, problems were occurring in motorcycles with combined engine and transmission oil sumps. The MA specification was launched in 1998 with the attempt to differentiate between products that were suitable for wet clutch applications and those that weren’t. This was done in collaboration with the major motorcycle manufacturers of Japan at the time, so it was a fairly industry-wide desire to identify the products that worked most effectively. The first two categories introduce by JALOS were the JASO MA and the JASO MB performance specifications. The MA category was originally meant for good clutch compatibility and MB was for products not compatible with wet clutches, or in other words; products that contain friction modifiers and cause clutch slipping.

       In 2006 the T903:1998 specification was replaced by the T903:2006 specification which underwent a big change to the clutch friction test results and their interpretation. The MA specification for JASO performance in wet clutch applications was further broken down into three oddly distinct yet overlapping categories. In 2011 the T903:2006 specification was then replaced by the T903:2011 specification in order to further refine those friction result ranges for each category. The charts below lay out the exact ranges for each category during each update and make it simple to see how they are currently broken down.

JASO-T903-1998-chart.png

Table 1: JASO T903:1998 Clutch Friction Specification

JASO-T903-2006-chart.png

Table 2: JASO T903:2006 Clutch Friction Specification

JASO-T903-2011-chart.png

Table 3: JASO T903:2011 Clutch Friction Specification

JASO-T903-2016.png

Table 4: JASO T903:2016 Clutch Friction Specification

  • MB – To be classified as MB, at least one of the three results needs to be within the MB ranges. It can be any one of the three, it could be two of three or it could be all three, but at long as at least one result is within the MB range, the entire oil performance is considered MB.
  • MA1 – To be classified as an MA1 oil, all three of the results must be within the MA1 range.
  • MA2 – To be classified as an MA2 oil, all three of the results must be within the MA2 range.
  • MA –  To be considered MA, all three results must be within the MA range. Since the MA range encompasses both the MA1 and the MA2 specifications, it can become a little confusing. Technically, if a particular oil meets the MA1 specification, a lubricant marketer can call it an MA oil and the same applies to an oil that meets the MA2 specification. If an oil’s results are mixed and some of the results are within the MA1 range and some are within the MA2 range, then it can only be classified as MA.

       So that is how the clutch compatibility is currently tested. The SAE #2 bench test is the most current testing protocol to determine performance at the time I am writing this article. To put it simply, MA covers the entire clutch compatible range, MA1 is the lower friction half of that specification and MA2 is the higher friction half of that specification. These friction test results are the only differences between the four JASO categories for 4-stroke motorcycle engine oil.

       The result names of DFI, SFI and STI are kind of nondescript and difficult to assign a practical property to. It took me quite a long time in the industry before I found a adequate enough description of each one to fully understand the results myself. Here is a basic description of what each one means:

Dynamic Friction Index (DFI) – Is a measurement of how power is transferred while being operated under slipping conditions or in other words, how the clutch feels as it is engaged when already spinning.

Static Friction Index (STI) – A measure of how much torque can be applied to an already fully engaged clutch before slipping occurs.

Stop Time Index (STI) – A measurement of how much time it takes for the clutch to engage when the lever is released.

    There are other tests that are required for JASO compliance that relate to performance characteristics other than wet clutch compatibility tests. Here is the exact specification followed by a brief description of each item. (Warning: there are a lot of technical terms coming up that you might want definitions for, many of these terms and tests are already listed in the glossary page at Mototribology.com.)

JASO T903 2011 test specs.png

                              Table 5: JASO T903:2016 laboratory bench testing requirements. These specifications control the chemical and                                   physical properties of motorcycle specific oils.

Density – A measurement of mass per given volume

Flash Point – A way to measure the flammability characteristics of a fluid. It is measured by determining the temperature at which the oil vaporizes rapidly enough to make the volume of air directly above the liquid flammable.

Kinematic Viscosity - A measurement indicating a fluids ability to flow. The more viscous oil is, the thicker it is. This is sometimes referred to as low shear viscosity. While the result at 40°C only needs to be reported, the result at 100°C must correlate to the designated SAE viscosity grade on file for the product.

Viscosity Index - A number which is calculated using the kinematic viscosity of a fluid at varying temperatures. Simply put, it is a measure of how stable the viscosity is over a wide temperature range. The higher the viscosity index number is, the more stable a fluid is with regards to viscosity.

Low-Temp Viscosity, CCS – The low temperature viscosity of an oil in high shear rate conditions.

High Temp. High Shear Rate Viscosity at 150°C (HTHS) – The high temperature viscosity of an oil in high shear rate conditions.

Sulfated Ash – The metallic ash content of an oil after it burns. This is a part of how to evaluate an oil’s cleanliness.

Acid Number – The acidity of an oil. This is sometimes referred to as Total Acid Number.

Base Number – The alkalinity of an oil. This is sometimes referred to as Total Base Number.

Evaporative Loss – The mass of oil that will evaporate at a specified temperature. This relates to oil consumption rate and an oil’s viscosity stability.

Foaming Tendency – The resistance an oil has to a head of foam both forming and persisting on its surface measured at three different temperature conditions.

Shear Stability – The resistance for an oil’s molecules to be sheared or reduced. This property relates to viscosity stability.

Color – I sincerely hope this needs no description

Elemental Analysis – A quantitative measurement of the concentration of chemical elements in a material. Phosphorus is the only element that is controlled or limited by JASO.

Infrared Absorption Spectrum Analysis (IR Scan) – A type of scan that identifies chemical bonds.

IR Example.png

Figure 1: Example of an IR scan

       This stuff can be confusing, I know. So if any of it is still unclear to you, feel free to PM any questions.

      You may have noticed that most of the tests on this list are only reported to JASO and don’t actually have any required values. This is because many of these tests are simply used as identifiers. JALOS periodically does “secret shopper” testing and pulls products off the shelves to make sure that the oil being sold matches the formula which was filed with JALOS. This has the dual purpose of ensuring that the originally filed results were accurately reported and that formula changes were not performed without re-qualifying the oil with JALOS. With so many different properties being reported, it would be easy to identify a simple manufacturing variance compared to an actual formula change, so it effectively keeps lubricant marketers from being dishonest when advertising a JASO registration.

    So that is the entire JASO 4-stroke engine oil specification minus the labeling requirements and then all it takes is a deposit of ¥40,000 (approximately $400 USD) to the JALOS bank account to be added to their list and to display a JASO box such as the one below on the back label of an oil.

JASO box.png

Figure 2: JASO registration box for rear labels of motorcycle engine oils.

Only products that are officially registered with JASO and are included on the JASO filed engine oil list are permitted to display this box on their label. So if you see the box, you should be able to look it up on the list to confirm its registration. You can also find the company that owns each formula and if you read the oil code you can tell exactly what country that product is manufactured in. By looking at digits two, three and four of the oil code, which are specified by a corresponding country code in Appendix 3 (Page 19) of the JASO T903:2011 specification document, you can tell the exact country of origin for every product on the list.

JASO Oil Code.png

Figure 3: JASO oil code example.

Why JASO is Important

Now you may be asking yourself, is registration really that important? It is true that registration is not required to market a product for 4-stroke motorcycle use, but the fact that a product is registered does give assurance from an independent third party that a product does perform as claimed. There are many many brands and products out there that claim to “meet JASO MA requirements” or they may say “meets JASO performance specifications” or something else along that same line. If there is only a claim and no box, then you simply need to take that company’s word for it that they comply, and if there is no official registration, it is only that company’s promise that they are formulating honestly. The products that claim to meet JASO requirements more than likely do, but there is certainly a higher chance that a company that does not register may not be testing to ensure that performance.

Registering with JASO does have a downside. It makes it difficult to improve formulas any more frequently than once every few years because of the cost involved for each reformulation, so it can make it difficult to adapt to quickly advancing technologies.

The JASO specifications give a benchmark for motorcycle specific oils that highlights the performance needs that are different from standard automotive oils. By addressing those differences and working with both motorcycle manufacturers and lubricant manufacturers, JASO continues to update the specification every five years or so to remain in step with the most up-to-date technologies; by keeping up-to-date with the technology advancements always happening, it makes sure that oils are able to advance without risking the loss of their JASO registration simply for trying to improve or do things possibly outside the ordinary to create a uniquely performing product.

What’s Next?

       The T903:2016 specification was released in April, 2016 and is now implemented. There was an attempt to bring in a new test to quantify gear protection, but there were problems validating the test procedure so it is not planned to go into effect until 2021 now.

       The clutch test was revised to give a more accurate differentiation between the categories. So the updated ranges and test pieces now offer a more precise and useful test.

       As mentioned above, gear pitting is an issue they want to address. It was not able to be implemented in the 2016 specification but it is still of interest for eventual inclusion into the specification.

       The FZG Gear Test was the original test considered to analyze gear pitting performance. Unfortunately the FZG test method proposed for measuring pitting protection has been deemed too unreliable to be standardized. There is a lack of repeatability between laboratories performing the test and the cost of each test was determined to be too costly in the end.

       An alternative test called the Thrust Needle Bearing Test has been suggested as an alternative to the FZG as an indicator of gear pitting protection. The test result has a close correlation to the FZG results and is very cheap to run relative to the FZG gear test. Unfortunately this test is also experiencing a lack of repeatability between laboratories at this time.

       Unfortunately before the specification can include a new test, the test must display a strong correlation between facilities and a highly repeatable test method. Different users and laboratories must be able to obtain results within a reasonable margin of error, but until that happens, this new test will not be part of the specification. By 2021, they may have a new procedure developed that can work for this purpose.

Here are some links to the JALOS website for anyone who would like to review the official documents:

JASO T903:2016 Specification

JASO 4T List of Filed 4T Engine Oils

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On 3/26/2017 at 8:10 AM, Jeffrey Torgalski said:

I just looked my recommended oil up on Amazon and compared it to your list, and the ratings from the bottle weren't the same as what's on the list;

https://www.amazon.com/dp/B008MISDII/ref=olp_product_details?_encoding=UTF8&me=

JALOS typically updates their list on a monthly basis, so their list should be the most up to date. It states the published date on the top of the page if you are interested in finding out the date that particular list was published.

Sometimes, manufacturers have leftover inventory from previous formulas that may hold different certifications or registrations than what is currently available, so it may just be some slow moving product that has been on the shelf for a while. Usually if you register a new product with JALOS it supersedes the registration for the previous formula, so the numbers may need updating on the new bottles, but the older ones met the original requirements.

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2 hours ago, MotoTribology said:

JALOS typically updates their list on a monthly basis, so their list should be the most up to date. It states the published date on the top of the page if you are interested in finding out the date that particular list was published.

Sometimes, manufacturers have leftover inventory from previous formulas that may hold different certifications or registrations than what is currently available, so it may just be some slow moving product that has been on the shelf for a while. Usually if you register a new product with JALOS it supersedes the registration for the previous formula, so the numbers may need updating on the new bottles, but the older ones met the original requirements.

At least I understand that part. :blink:

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My guess is that many of those oils listed for bikes are simply common oils that have been relabeled so they can charge a higher price for them.

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10 hours ago, Weezer the Geezer said:

My guess is that many of those oils listed for bikes are simply common oils that have been relabeled so they can charge a higher price for them.

I suppose that is a possibility, but I certainly wouldn't use that company's automotive products if that were what I believed.

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21 hours ago, Weezer the Geezer said:

You may understand oils, but not sure you understand corporate marketing.

You have to understand the OP is an Amyway Oil salesman that was recommending car oil for everyone's motorcycles, so it would seem you have him pegged! :thumbsup:

 

What is JALOS anyway?

Edited by Bermudacat

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On 3/31/2017 at 2:59 PM, Weezer the Geezer said:

You may understand oils, but not sure you understand corporate marketing.

I guess that's why they keep me in R&D and out of the marketing department.....:rolleyes:

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soooooo, i take it using an unlisted lube from a manufacturer catering to hd diesel equipment that claims jaso ma/ma2 rating, and then taking the japanese rating and using it toward an austrian bike, might be a little counter-intuitive?

i admit i feel quite silly now that i have learned from this post.

 

thank you

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3 hours ago, 92dlxman said:

soooooo, i take it using an unlisted lube from a manufacturer catering to hd diesel equipment that claims jaso ma/ma2 rating, and then taking the japanese rating and using it toward an austrian bike, might be a little counter-intuitive?

i admit i feel quite silly now that i have learned from this post.

 

thank you

Taking a lube manufacturer's word for it is just that. If you trust the manufacturer to be truthful (and in today's world of litigation it's more likely than ever before) the product does likely meet the standards they say. I don't personally use diesel oil for several reasons which I'd rather not get into right now, but that isn't to say I won't try it at some point. The testimonials and data I've seen just leave something to be desired for me.

 Your issue of the Japanese ratings for a European made bike you shouldn't fret over. The JALOS organisation originally spearheaded it because of how prevalent motorcycles are and how important the motorcycle manufacturers are to their economies, but there is cooperation among manufacturers from all over the globe now and I think just about all of them specify some compliance with JASO specs (at least when a wet clutch is involved).

I think that was what you were asking but now that I read it over again I fear I may have missed the point. Feel free to PM if you'd like to discuss it further.

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no, you got it! no sarcasm or any sort of word trickery involved lol.

 

last line should have read more like, "i feel silly for not paying attention to labels,  now that i have learned better from your article."

with the genuine "thank you" for writing it lol.

 

the diesel oil has been a one time experiment and my 15 hrs is almost up before i scrutinize filters and screens. i will not do uoa because i have no baseline (bike bought used, with guessed hrs)

 

anyway, i will likely go back to motorex though i hate the expense

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And I will stick with the cheaper, regular automotive brands as I have since since the 1970s.  Being sure to not get a brand with antifriction additives to interfere with wet clutch action.  My decision is due to decades of experience, talking with oil distributors, and friend's who are top notch mechanics and race car drivers who were not being paid to promote a certain brand of oil.  I have in recent years switched to synthetics.  They seem to hold up better and don't evaporate as quickly.

Okay.  You can attack me now.  I have heard these arguments for decades.

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      Table 2: SAE J306 Gear & Transmission Oil Viscosity Specification
      The two tables presented above are the one and only standard way to classify engine and gear oils in the motorcycle lubricant industry. There are other ways to categorize products for use in industrial applications, but they have no place in these discussions. Oils can either be mono-grade meaning they only claim to meet one viscosity specification (ie. 80W transmission oil and 50 weight engine oil) or they can be multi-grade meaning they meet the specifications for two of the classifications (ie. 5W-40 and 25W-60). The specifications are created so that only one winter grade and one weight can be claimed at any point.
      Many believe that the winter grade designates how thick an oil will be, as in thinking a 10W-50 will be thinner than a 20W-50 but this is not true. Remember, the winter grade only correlates to an oils behavior at subzero temperatures. The fact that the two oils are 50 weights says that they need to meet the same viscosity range at high temperature. That being said, the tendency for an oil to have a lower viscosity at low temperature (which is desirable) does tend to also make it seem thinner at room temperature so this is where this myth probably originates, but most people see the oil at ambient temperature as they pour it out of a bottle and not as it pumps through a motor at 100°C so it is an understandable belief. However, this is the fact to take away, any 50 weight engine oil (or 20, 30, 40 or 60) behaves exactly like any other 50 weight engine oil (or 20, 30, 40 or 60 respectively) at the operating temperature of an engine. The lower the “W” grade of an oil, the more thermal stability it generally has which is a desirable property in oils, but it is not a given so I don't recommend assuming one oil is better than another just based on that property.
      Viscosity is the most basic property of oil and it is without a doubt the most important feature of any oil. Using the appropriate viscosity oil is the first correct choice to make in selecting any lubricant for use in your machines. The machine manufacturers designed the engine or gearbox to operate with a specific lubricant so things like the oil channels, oil pump and clearances are all specific to the recommended grade of oil. The one and only exception to this is the winter grade. You can always go to a lower “W” grade as long as you maintain the regular grade (ie. you can use a 10W-50 instead of a recommended 20W-50). You can sometimes go to a higher “W” grade as well, but that depends on the application and environment and is only advised when the climate does not approach freezing temperatures.
    • By MotoTribology
      Grease is a tool used so universally around the world but remains somewhat of a mystery for many of the people who use it. Every motorcycle needs grease at some point and there are several different areas where it is applied. Although grease manufacturing is a somewhat complex process it is somewhat seen as an art and each company’s methods and exact formulas are different. This results in sometimes subtle but sometimes drastic differences in products.
      The basic formula for grease is this: base oil, thickener and additives.
      Base oils can be anything from petroleum to synthetic to plant based oils. There are several different commonly used thickeners. The most common types are lithium, aluminum and calcium sulfonate. The additives used are dependent on the type of grease and the purpose of the grease. Base Oil:
      The base oil composition of a grease will impart a few crucial properties:

      Table 1: Basic base oil comparison
      The reason synthetics are less versatile than non-synthetic base oils is because of synthetic types likes silicone and poly-alyklene glycol (PAG). These types of oil are usually only meant for very specific industrial applications and are unsuitable in many others, so care is needed when selecting grease to avoid these types of synthetics in many instances. With that same reason in mind, additive selection is also more limited with these alternative synthetic options. However, plant based oils are still generally less versatile due to the temperature constraints they are typically limited by to.
      Thickener:
      Different thickener types have different performance attributes distinct to each type. Here are the most common types of base grease thickeners used for multipurpose motorcycle greases.
      Lithium offers a good water resistance, heat tolerance and mechanical stability. It is currently the least expensive type of grease to make so it is very prevalent in the marketplace. The drawbacks of it compared to other types are that it is not completely waterproof and will accept moisture over time.
      Aluminum is practically waterproof but is more expensive to manufacture than lithium grease. It offers high temperature stability, but is slightly less mechanically stable than other types.
      Calcium sulfonate has excellent high temperature, low temperature and inherent properties that allow it to use fewer additives to obtain certain performance levels. Its water resistance is excellent and it is often compatible with other greases. The big drawback to calcium sulfonate is the price. It is typically much more expensive than either of the other two types to produce.
      A grease complex is a variation of the standard base grease that is possible to make with lithium and aluminum. Aluminum and lithium complex greases exhibit higher temperature limits and better mechanical stability than their uncomplexed counterparts.
      All three of the grease types listed are often compatible with one another up to around 25% contamination with one type and 75% of the other. Beyond that 3:1 ratio though, incompatibilities are more common and certain properties may be sacrificed if mixed.
      There are many other types of thickener types I haven’t mentioned but those are rarely, if ever, used for the types of greases commonly used for motorcycle.
      Additives:
      Common additives for greases include: anti-oxidation, anti-corrosion, anti-wear and extreme pressure(EP) additives. Additional types are certainly used, but those are going to be found in a lot of greases with perhaps the exception of extreme pressure additives if the grease is not labeled as EP grease.
      One last fairly universal additive is dye. Most greases are dyed some color and many people believe these colors mean something. Let me be absolutely clear here so there is no confusion; THE COLOR DOES NOT MATTER. The colors are arbitrary and chosen by the manufacturer for aesthetics and nothing else. They may have their own standards and reasons for why they color certain grease a certain way, but it is not to conform to any industry standard.
      Grease Applications & Properties:
      Grease has some advantages over oil in certain applications. It can be applied in open areas without a sump or reservoir. It forms a significantly stronger physical barrier on a surface making it more suitable in extreme applications. It can utilize solid lubricants more effectively than liquids can.
      There are basically two types of greases commonly used in most motorcycles. They are assembly grease used during engine building or repairs and multipurpose greases for everything else. Multipurpose greases are usually good for bearings, axles, pivots and really any grease point on a bike. Assembly lubricants usually contain a high level of solid lubricants and provide lubrication to machine internals that are normally lubricated by oil or special applications that require a high content of solid additives.
      The purpose of assembly lubricants is to provide lubrication on parts that have never been exposed to engine or gear oil yet, so when the bike is started for the first time after maintenance; those parts have some protection before the regular lubricant begins circulating. These assembly greases are usually washed away by the oil and are removed from the system during subsequent oil changes. Another application for these products are areas such as final drives where a high content of solid additives can be beneficial for surface protection.
      Most grease points on motorcycles are fairly low load compared to more extreme grease applications in commercial applications. This means specialized grease is rarely needed and a single multipurpose grease is usually able to serve all of those grease points. They go into places that are open and exposed, high load or in places that oil films cannot be maintained. Bearings, axles and chassis linkages are common applications for these greases. They generally will provide extreme pressure protection and decent anti-wear protection. Because they form a physical barrier against water and oxygen, corrosion protection is inherently high, but this is also often boosted further by additives to protect against rust and corrosion. They should maintain a physical barrier to keep out moisture and dirt from these applications that would self destruct very quickly if contaminated. Grease does all of this through both physical and chemical means and there are a few key points to consider when choosing the right grease for your application.
      First and foremost is the grease consistency or hardness. This property for grease is just as important as the viscosity is for oil. Using an incorrect grease consistency can quickly result in part failure and under-lubrication.
      Grease is categorized into different grades by the National Lubricating Grease Institute (NLGI) scale based on a grease’s penetration test result. Grease penetration is a measurement of the depth at which a calibrated metal cone will penetrate into the surface of grease when dropped form a standard height. Penetration is represented in decimillimeters (tenths of a millimeter), and the penetration is often taken under two different conditions: worked and unworked.
      An unworked grease is fresh from the container and has never been used. A worked grease is one that has been put through mechanical stress to simulate usage. The purpose is to indicate the stability of the grease with regards to its consistency. Working grease is a standard process that involves a piston churning the grease a standard number of times using an instrument known as a grease worker. The standard method uses a plunger with 60 holes in it and it is pushed a pulled a total of 60 times in 1 minute.

      Figure 1: Mechanical Grease Worker (please imagine there are 60 holes in the piston face)
      After that minute, the grease is considered worked and can now be tested for NLGI consistency. The grades identify significant differences in the hardness or softness of greases. The simplest way I find to describe them is to compare them to common foods.

      Table 2: NLGI grades and consistencies.
      Another important property of grease is the base oil viscosity. During the manufacture of base grease, the ingredients of the thickener are mixed with oil. When the grease reaction takes place, that oil becomes part of that grease. Typically the higher viscosity the oil, the more heavy duty application it can withstand. However higher viscosity base oils usually limit the low temperature performance, so for general purpose grease, a base oil blend balanced for moderately high and low temperature performance is preferable.
      Assembly grease typically contains a high level of solid lubricant meant to withstand high pressure and remain in place in the absence of the regular lubricant that would normally protect the surface. The reason this regular lubricant needs replacing is usually because the machine is rebuilt and hasn’t had the oil circulation system running yet. These greases don’t need to have a very long usable lifespan since they are designed to be used up fairly quickly, washed away by the oil and removed by either a filter or through the next oil change. Therefore, anti-oxidation and long term stability are not key features for assembly lubricants. However, another application for assembly greases comes from the typical high level of solid lubricants. Since these solid lubricants will resist extreme loads there are applications in some bikes that call for a grease like this such as final drive shaft gears.
      Grease application is an aspect that a lot of people have difficulty with as well. I often see comments implying to just pump in as much grease as a bearing can hold and that is how much it should use. That advice is almost universally bad. Over-packing a bearing can lead to some very bad failures. Alternatively too little grease is also a problem for more obvious reasons; under-lubrication and all that goes with it being the biggest of them. You can read about the pitfalls of these mistakes and how to avoid them here.
      So I hope that gives you a good basic starting point to look at greases and you are now armed with the knowledge to at least ask the right questions when trying to choose between different brands of grease.
    • By MotoTribology
      History:    
           The brief history of the Japanese Lubricating Oil Society (JALOS) with regards to 4-stroke requirements was described in JASO Explained: Part 1. A lot of the same reasons were given for the formation of the JASO M345 specification for 2-stroke oils as were given for the T903 specification for 4-strokes. At the time, there was a lack of control for performance levels of available lubricants and JALOS decided to form a specification that was designed specifically for motorcycle applications in the void left by other standards being discontinued. This gave the OEMs a standard to specify for use in their products that ensured their machines would not fail from inadequate lubrication.
           Prior to the JASO M345:2003 specification, the National Marine Manufacturers Association TC-W performance level was created in the 1960’s but focused on outboard and marine engine oils. The American Petroleum Institute (API) released specifications starting with API TA to API TC throughout the years, but in 1994 JALOS superseded the API specifications with the JASO FA, FB and FC specification levels. This release of new specifications was partly in response to the API discontinuing any progression to the API 2-stroke specifications ending with API TC in 1993. Another set of specifications developed by the International Standards Organization (ISO) are similar to the JASO specifications for 2T engine oils with some minor differences, and I’ll elaborate on those differences later in this article.
           After the FA, FB, and FC specifications, JALOS introduced the JASO FD specification to advance lubricant technology to an even higher standard and at the same time made the FA specification obsolete. So the three levels of performance currently maintained are FB, FC, and FD according to the JASO M345:2003 specification.
      Specification Details:     
          The JASO two-stroke specifications are important because they create a benchmark for minimum performance criteria for 2-stroke oils. This particular category of products may just have the largest variety of properties and formulations in the motorcycle market. Many lubricant companies have their own methods for formulating 2-stroke oils and in doing so have developed many unique solutions to the main concerns of 2-cycle lubrication. Regardless of how the performance is accomplished though, what they need to accomplish is set by JASO in no uncertain terms.

      Figure 1: JASO M345:2003 specification for 2-stroke engine oil performance
           The numbers for Lubricity, Initial Torque, Part Detergency, Exhaust Smoke and Exhaust Smoke Blocking are all index numbers associated with scores associated with performance in each category. For each one, the higher the number is, the better the performance in that category.
      The general rules for the different performance levels are these:
      FB corresponds to high lubricity performance but without any low-smoke technology. FC meets the FB lubricity standards but also is a low-smoke lubricant. FD corresponds to higher detergency properties than the other two grades, meets the lubricity requirements and has low smoke requirements.      Most of the performance testing is performed using standard test engines and measured by part raters following the JPI-5S-34-91 rating manual. Part rating is a very exact method of evaluating engine parts after use to determine their condition and raters are highly trained to perform this duty. Each of the methods uses specific engines for evaluation.

      Figure 2: JASO M345:2003 test methods and test engines
       
      The M340 test measures the lubricity and friction characteristics of the lubricant. Less friction means less heat generated from friction and may increase component life greatly by doing so. It may also contribute to lower wear, although this is not always the case as friction and wear are different and are often addressed by different parts of the formula. The M341 test measures the detergency of the oil which corresponds to its ability to remove existing deposits and prevent new deposits from forming on internal engine parts. The M342 test evaluates how much smoke is produced by an engine using the test oil. This test is partly for environmental reasons but also affects performance. Smoke does not often exit the exhaust cleanly and will leave soot in the exhaust system changing the geometry and surface characteristics. The M343 standard tells us what the exhaust smoke’s effect on engine performance is. With the exhaust system playing a big part in engine output in 2-cycle engines, soot and carbon buildup can affect that performance negatively if not controlled. The sulfated ash measurement assesses the oil’s contribution to ash formation caused by metallic additives that cannot fully burn. Many 2T oils utilize “ash-less” additive systems to eliminate this issue, but they are not required so this measurement is important. Flash point measures the temperature at which the volatile vapors given off by a lubricant are produced at a high enough concentration to ignite with a flame source. This may indicate how well an oil will burn or remain unburned in a combustion chamber. Many oils utilize solvents in their formulas which may give a low result not indicative of the actual lubricating oil so be aware that the reported flash point may not tell the whole story. I would recommend finding the flash point of a 2-stroke oil without its solvent component to get its true contribution to combustion. Kinematic Viscosity at 100°C is a measurement of the thickness or fluidity of the oil and contributes to oil film strength.  
           The reason JASO M345 is in need of an upgrade is because of the two test engines used in Figure 2. The engines used for the tests are being discontinued and spare parts are becoming difficult to source in order to keep those motors running at the necessary performance level. Without standardized parts from the manufacturers, the engines cannot be kept running in adequate condition for the tightly controlled JASO testing.
           New engines are being tested and evaluated for standardization, and the next update is scheduled to go into effect in April of 2018. The original plan was to update the specification with new test engines in April of 2016, but JALOS announced that they were pushing back the launch date to 2018 due to repeatability problems. The Yamaha ET-1 engine is currently the leading candidate for inclusion, but testing is still underway to ensure compliance with the strict standards for the indexing of various properties measured by the JASO M345 specification.

      Figure 3: Yamaha ET-1 engine. Photo source: http://global.yamaha-motor.com/business/pp/generator/220v-50hz/0-1/et-1/
           Because of the uncertainty in this engine’s ability to provide repeatable and reproducible results, the specification is being pushed back until its results can either be verified or a different test engine can be identified, so don’t expect anything new until 2018. It was unclear what kind of performance advancements the new specification would have incorporated before this delay, but it appears there is a plan to separate smaller displacement engines such as brush cutters, chainsaws and other handheld equipment from vehicles with separate criteria. For the time being though, engines and parts are still available for the current test engines so new lubricants can still be evaluated accordingly to the high standards that are already in place.
           Before I finish this article, I do want to briefly mention the differences between the JASO and the ISO specifications for 2T engine oils because it is a distinction worth mentioning.

      Figure 4: ISO 13738 specification for 2-stroke engine oil performance
           The ISO L-EGD and JASO FD are the exact same performance specification. The differences between ISO and JASO are in the B and C specifications. The ISO L-EGB and L-EGC specifications each have an additional detergency requirement. This means the ISO L-EGB and L-EGC specifications require higher performance levels than the JASO equivalents, but most oils that meet JASO requirements will also meet the ISO requirements, so there is rarely a difference between an oil claiming ISO or JASO performance levels.
      Review -
          So after all that your head is probably spinning trying to figure out what all of that means. So to boil it all down I'll try to sum it all up here:
      The JASO specifications indicate increasing performance levels with FB, FC, and FD specifications. The requirements include lubricating ability, cleanliness, smoke potential, and a few physical properties. ISO and JASO are essentially the same with a few minor differences. The performance specifications give machine manufacturers real and tangible minimum requirements to maintain their equipment and ensure high performance. With these specifications, we can look at specific performance differences between products to determine which is the best for our machines without having to rely on uncertain performance claims by lubricant companies or machine manufacturers. Useful Links -
      JALOS M345:2003 Specification manual
      JASO M345 Registered Lubricant List
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