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dirtdad

Motor Oil

33 posts in this topic

Very good article, I am very interested in the topic and have read many of the zillion posts on this subject.

I have had street machines for many years and always ran Castrol 20-50 summer and 10-40 winter (it gets cold in KS-easier starts) and never had a problem with clutches or loss of power. I even ran the synthetic Castrol once an a while just could not afford it all the time..

Anyway my 98 yz400 is my first dirt machine and I bought the 4-stroker because it would be easier to ride and it was and because it would not have to be re-ringed every other month...

Does anyone really run regular motor oil in their dirt bikes or what? I really want to try some Castrol synthetic or some mobile1 as I hate to pay the extra $$ for Yamalube which does not look to good when I change it after 3 or 4 hours.

Whas the real skinny here folks?

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Tom N, I've really learned alot about motor oil since I joined this forum and bought the big four stroke. In the past I never really gave it much thought with previous bikes. I just always used the recommended oil. If you look in your manual, it RECOMMENDS Yamalube but at the bottom it states "or SAE 20w40,10w30(whatever applicable viscosity) type SH (or higher) motor oil (non-friction modified). I took a trip to the local auto parts store yesterday and went through every bottle of oil they had available. I found that about half of all the different types/brands available were non-friction modified, making those oils suitable (maybe not optimum) for use in our motorcycles. You can tell that by looking at the little circle at the bottom on the back label of the oil bottle. The bottom of the circle will have energy conserving written in that space. It also tells you this in the manual. it states under CAUTION: Do not use oils labeled :ENERGY CONSERVING II" OR HIGHER.

It also gives a picture of the label and what to look for. One thing that the manual does NOT state (at least I can't find it) is to not use full synthetic oil. It just states "do not add any chemical additives or use oils with a grade of CD or higher as these could cause clutch slippage. This is also illustrated in the picture. Of course Yamaha recommend Yamalube (good business), but they don't say to use motorcycle specific brands/types. They really only state what not to put in it! Hope this helps. I know, I know...clear as mud!

bottom line is there's alot available out there to use in this bike. You can either use what's recommended by others based on their good experience with a particular brand/type/viscosity or go out and look at the bottles yourself (I recommend doing that anyway just to be sure).

[This message has been edited by dirtdad (edited 03-12-2001).]

[This message has been edited by dirtdad (edited 03-12-2001).]

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WOW! I feel very honored that I found some info that actually helped you Hick! Usually I'm the one reading your posts to get the straight poop. I'm glad some of you found this useful.

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Thanks for the article.

I wanted to add some thoughts to this string since most of the oil topics seem to fail to make some essential conclusions.

There are two issues that I seldom see discussed. The first is - why oil needs to be changed, and the second is - the relevance of oil viscosity for your application.

Engine type and application cause variances between the two reasons why we change oil. They are "contamination" and "breakdown".

Contamination is caused by combustion chamber gases and their particulars getting into the crankcase and therefore the oil. This causes chemical changes in the oil and also adds physical particles too small to be filtered.

Breakdown is the loss or burn out of the additives that are combined with the oil when the oil is formulated, it is not the break down of the oil itself. Each type of oil has it's own list of additives, (formulation) of which some are used as anti-foaming, whereas others are used for environmental concerns.

By the way, (just to prevent this debate) in some cases oil itself can breakdown returning to carbon, but only in extreme conditions such as the infamous TV commercial frying pan - something we'll never see unless we decide to run our bikes on a pint of oil or have an extreme component failure.

In most non-performance automotive and moto-street applications, the oil will become contaminated at about 2500 to 3000 miles. Breakdown begins at about 5000.

The distinction to higher performance application and the effects on the oil is based on significantly higher RPMs that are maintained when the engine is in use, since this exponentially adds contaminants to the oil. In these applications, the oil is good for about 400 to 600 miles at best, although the additive breakdown would not occur until much later.

Therefore we answer our first question. Due to our engines and riding styles, we need to change our oil more frequently due to containments, (not breakdown) and we should be less concerned about most common usage additives and their claims.

How often is often? If you race, I would say every two to three motos. If you hard trail, I would say every 10 to 15 hours of usage.

Now onto the issue of viscosity. This is a measurement of how much oil will flow past a given opening at a particular temperature. This is most relevant in applications of cold start, where most of the engine damage is done since the oil is seldom present until circulation begins.

The thinner the oil, the better the oil will circulate at cold temperature. This is where most automotive and street moto manuals will show different viscosities for different times of the year mostly applicable for those that live in extreme season to season climates - like New York or Boston and not those that live in the LA or San Diego areas.

Viscosity is extremely important for vehicles that go through the stopped-cooled-and started cycle on a regular basis. By the way, multi-viscosity oils are achieved chemically, which means this benefit will breakdown over time.

There is also a debate that can be made for viscosity to that of engine design, (tolerances and the like) but let's not go there.

So back again to the relevance of viscosity to high performance usage. Ever wonder if the teams of Jeff Gordon or Michael Schumacher change the oils in their cars from 20-50 to 10-40 when they race at colder temperatures? The answer is no. The reason why is that they start the engine, they race like hell, then they shut the things down and it’s the end of the day and the end of that oil. Very close to the same manner in how nearly all of us use our bikes.

Now if you use your WR for getting firewood every day, or have a street conversion, you need to pay attention to viscosity.

So this intuitively takes us to the question of what viscosity we should run if the cold-start cycle is not relevant? That then takes us back to the engine design which takes us right back to the engineers that designed the bike which takes us right to the manual. In other words, we need to run at a viscosity at a max rating of no more than 40 or 50wt for our application. Hence the rating of the 4 stroke Yamalube.

Lastly, there are some remaining issues of oil additives that can cause problems with engine internals. These are compatibilities with clutch friction discs, seals, metals, tolerances, and fuel types.

I can’t speak for Yamaha and the complications of this engine design, but we do know that most clutch friction compounds seem to perform nearly as well with all types of oil. If they didn’t, we would see it in the oil and on the friction disks, and we may even feel it when riding. Same things with seals and composites of the metals.

So the bottom line is that it’s good to read as much as you can on all subject matters, but do make sure that you understand how it applies to you and your machine.

Hope this helps.

DaveJ

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DaveJ, Good stuff. I sometimes take for granted that everyone understands the common terms used (ie: viscosity, etc.) and the reasons for oil changes. I tried not to go into that great of detail when I wrote my reply to TomN. Good info you added though.

------------------

like a kid again!

00 YZ426F

01 TTR-125L (my son's)

91 CR125

83 YZ490

74 Hodaka Super Combat

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DaveJ,

Interesting info. on the variable viscosity in Schumacher’s race car, that makes perfect sense. So why does Yamaha recommend a variable viscosity oil?

I don’t ride my YZ like a grocery-getter, but often while out play riding (not training, racing or trail-riding) I stop my bike fairly often to watch other guys tackle some hill or jump, then re-start and do them one better (or crash). Is this what Yamaha had in mind when they recommended multi-grade?

Also, I’d been told that the “chemically attained” variable viscosity ranges would break down over time. The logical leap I’m making is that the narrower the range, the better it would hold up, i.e. we should avoid 5w-50, therefore wouldn’t 20w-50 be better than 15w-50? Or is this a nit?

The article linked by DirtDad indicates that ALL brands of a certain viscosity type will/will not have the EC additives (i.e. any 15w-50 will not have EC label, not just Mobil 1). Why is this? Some kind of EPA or SAE standard?

(gettin’ more smarter all the time)

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Prepare for another long one - I'm in writing mode.

I have some articles that I saved a while back that I reviewed tonight. Here's some more info.

A viscosity rating of 5W-40 means that the oil has a viscosity rating of 5 at zero degrees Fahrenheit and a viscosity rating of 40 at 212 degrees Fahrenheit, (212 is what they listed as the operating temp of oil). To make such an oil, polymers are added that swell at the higher temperatures.

So it turns out that Hick is correct about earlier break down of oils that have a broad viscosity range verses those with narrow ones. Therefore this benefit of the polymers would last longer in a 20W-50 oil than those in a 5W-50 oil.

Most of the articles that I reviewed indicate that a 40 or 50 rating (be that a multi or single grade) are used only for “summer” and performance applications. Most race oils that I look are 40, 50 and some of the single grades go as high as 60.

Last year when I was at Laguna for the big FIM/AMA Superbike event, I kept on eye on the oil changes of the factory teams. Surprisingly, most used Vavoline High Performance 20W-50 - an automotive oil. Even some that had a Shell or Agip sponsorship were using this. BTW, these bikes, with the exception of the Ducatis, all have wet clutches.

My point on Schumacher’s car was that most of us need not worry about moving from a 5W-30 to a 20W-40 due to seasonal changes. It’s more important for hot rods like us to have the highest performance oil at operating temps than be concerned about cold start issues.

As for cooling down while you hang out at the track, I don’t think it’s a long enough period of time for the oil to become thick enough to be an issue. I’ve drained oil from the bike after letting is sit for a few hours and it’s still quite warm.

I have also noticed that oils called “race oils” are starting to go from single viscosity to multi. Perhaps this extends the application of the oil, (a greater market – such as with Yamalube and the popular family versions of Yamahas four strokes) and I’ll have to assume that the added polymers don’t inhibit the performance of the oil for the way we ride. This is the only explanation that I can think of as to why Yamalube is a 20w-40.

Here's what I found about some of the other ratings.

Oils for all types of engines are rated by the American Petroleum Institute which is why you'll see API listings on most containers. The first letter indicates what type of engine the oil is designed for. An "S" is for gasoline engines; a "C" is for diesels. The next letter is the performance level of the oil based on a collection of their tests. The higher the letter, the better the performance of the oil. Therefore, an "SH" would be a better performing oil than an "SE".

Yamalube is SJ

Valvoline Performance oils are SG

Mobil 1 Synthetic is SH

There's also an "Energy Conserving" standard listed on the label as well. This should be the “EC” that Hick was asking about. In order for an oil to show an Energy Conversing listing, it must provide at least a 1.5 percent improvement in fuel-economy. To get an "Energy Conserving II" listing, the factor must be a t least 2.7, (the base is a standard 30SAE oil). This is achieved by friction modifiers added to the oil.

This is an automotive rating, so Yamalube does not list it. Check all other oils for a proper comparison.

As for additives, this is what I found.

Detergents and dispersants are added to hold elements such as sludge, carbon and other deposits.

Friction modifiers are added to help form a protective film on engine parts, reducing wear and improving economy.

Anti-foaming agents due just that.

Oxidation inhibitors keep this process from occurring when high heat causes oil to react with oxygen.

Alkaline compounds and rust inhibitors are added for moisture considerations.

And lastly, pour point depressants lower what is called the oil's pour point - the temperature that oil returns back to a plastic state and will not pure. I would have to assume this only applies to petroleum-based oils.

That’s enough huh?

DaveJ

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Originally posted by Tom N:

Does anyone really run regular motor oil in their dirt bikes or what?

Just a guess, but I’d say that here on TTalk there are just as many guys using Mobil 1 15w-50 as guys using Yamalube.

But after reading the article I’m thinking about switching to a 20w-50 synthetic, especially with summer coming up. The “EC” label is easily spotted on the container, and I’m thinking any full-syn oil of the proper viscosity that doesn’t have the EC additives will do. I’ll have to see what brands fit the bill down at Pep Boys or whatever.

That little voice in my head that was whispering, “Yamalube is a rip-off,” is really feeling his lungs now.

Thanks for the info DirtDad.

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Dirtdad, thanks for the info from the manual, all I have is the service manual and it does not have that much detail on the oil spec's - just shows a temp/viscosity range.

Hick your posts are always a learning experience - thanks!

DaveJ - Thanks for putting so much into this one for me. Now I have another question - I just want to make sure I understand you correctly as I think what you said along with everyone else it's starting to make some sense...

What I think your saying is that if the oil one chooses meets the viscosity rating from the mfg, is not friction modified, does not have the EC additives and meets the min. SH rating AND one changes their oil often enough it should not matter what brand or type one uses?

My mech kind of said the same thing to me when I asked him, he put it this way - "Compared to engine work oil is cheap - change it OFTEN, keep the air filter clean and you will never have a prob with the oil". When I asked about synthetic, he said "if youre changing your oil often enough the synthetic and its special properties/additives are not in the engine long enough to make a big difference - save the money go with Kendall or another brand and change it often". All your words and his do seem to make some common sense - I try and change my oil about every 3 to 5 hours of just regular riding (every time I go out for an afternoon of riding or after every race day (I race like a girl but getting better) so the oil is not in there long enough to break down and often when I dump it there is not much color change either.

So am I a getting whats being said between the lines here or am I missing the point?

Thanks again guys! :)

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By Jove, I think he's got it! :)

------------------

like a kid again!

00 YZ426F

01 TTR-125L (my son's)

91 CR125

83 YZ490

74 Hodaka Super Combat

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By Jove, I think he's got it! :)

------------------

like a kid again!

00 YZ426F

01 TTR-125L (my son's)

91 CR125

83 YZ490

74 Hodaka Super Combat

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Tom,

The bottom line is that Friction Modifiers don't seem to cause any concerns with wet clutches - and perhaps may even help with all the other mechanicals inside the engine.

So base an oil on its API rating and weight. Go with 20W-40 or 20W-50 with an API rating of SG or SH.

Then change often. After each moto may be extreme, but it depends on how long and brutal the racing is. I think 10 to 15 hours of riding is when I notice it's time for some new fluid.

DaveJ

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Wow, that was some interesting reading on that other board... whew.. Kinda funny though..

I think I am going to scope the labels of some Castrol or mobile1 for my next oil change. I ran castrol gtx for years in my street machines and was one to push 5k+ between changes.. I hate to say it but as a teen age rider I rode more worked less... I would wait until the gear box fetl rough and then change the oil and never had mech probs or clutch...

So I figure I will change often and see what happens..

oh yea just picked up motomadness2 for pc and its awesome, you can race a 426f or any of the KTM thumpers and is a great fix for when you can't ride.

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AZ Jeff, That's what happens when we try to share info. I for one like to have as much info on a subject as I can get. That makes me feel better when I form MY OWN conclusion on how best to approach a particular situation. There's always someone who beats his chest and refutes what you've offered based on their own narrow view of things. Keep sharing info!

------------------

like a kid again!

00 YZ426F

01 TTR-125L (my son's)

91 CR125

83 YZ490

74 Hodaka Super Combat

[This message has been edited by dirtdad (edited 03-14-2001).]

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Originally posted by Arizona_Jeff:

Yeah just look what I did over there at thumper central! Shame on me! Shame on me!

Jeff - Your post was well received by the VAST majority of people. As for the rest, I'm more than happy to deal with them :)

Rich Rohrich

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