Choosing the correct Oil for a wet-clutch Motorcycle

1. See my previous reply. If it's JASO MA (or better) compliant, then you can use it in any motorcycle of any age.
2. No. Synthetic oils do not cause oil leaks.

 

OK. It's just that in reading through this entire thread I haven't seen one person mention Rotella T-6 5w-40, even though the discussion of grades other than 10w-40 came up, and even though just about everyone mentioning Rotella talked about T-4, not T-6. And I've read elsewhere that full synthetics are not always recommended when it comes to older engines. But if the T-6 can't do any harm, or cause any leaks, then at least I know it's safe, although I'll probably get and use T-4 in the future since it does a fine job and is cheaper.

 

T-6 is quite new in comparison to the thread (as is T-4). When I first posted this info (prior to making this thread) Rotella had no sub-types; it was just Shell Rotella for airplanes, or Shell Rotella for diesels, and it came in a variety of weights.
I don't update or list which oils to use, because they change all the time; either by name or by formulation.
In the first post there is a link to the JASO website, which has a fairly comprehensive list (not sure if it gets updated often or not).
Otherwise, read the bottle and look for the certification and compliance marks. Everything else on the label is just shiny-shiny to get us to buy one brand instead of another.

 

Well...The T-6 is JASO DH-2 and JASO MA certified.

There was some discussion regarding the difference in weight -- 5w-40 vs 10w-40, and whether the 5w-40 was too "thin", vs 10w-40, but nothing conclusive was ever really discussed. Maybe it's a matter of personal preference and/or where you live. All I know is anecdotal evidence in that my buddy who has been refurbishing 3rd gen Honda Magnas swears by the T-6 and that's all he uses.

 

you can use syn oil. we have had a few here who used it then changed back because of starter clutch issues.
then there are others who used it with no issues.
I run T4 because it is within the spec range of oils for the old xj. i have no need for a 5W as I stop riding at 32 degrees F

 

Thanks. That was the kind of response I was looking for.

 

WOW. The synthestic oils that don't cause any troubles are the ones that are JASO certified or JASO compliant.
I guess I just suck at answering questions clearly anymore.

 

I think you answered clearly. I was just letting him know that there were a few who changed back from synthestic oil due to problems with starter clutch. I think that those who had problems were near the end of the starter clutch life to begin with.
oil is like gasoline some swear by a brand or type and thats what they use.
I just changed fuel brands and my podded bike feels like it is running better but that may just be the weather improvement warmer mornings.
with oil I am still going to change it based on Yamaha spec for miles, would rather save the few dollars for other things.

 

Apologies for the overreaction. The last six months of work have been unbearably aggravating.

 

Fwiw, I was using a synth 5w-40 in my GS a couple of years ago and it was quite good. The specced oil is 10W40, but there was always a bit of cold clutch drag, which is why I gave the 5W-40 a whirl; it worked really well to banish the cold clutch drag, an an unexpected (but not totally unsurprising) benefit was the sudden availability of a couple of extra horses at the wheel, which only goes to show how much internal engine drag plays a part in things.
I had planned to use the 5W-40 in winter and revert to a 10W40 in summer, but after the first winter using the thin synth, the base gasket started leaking like a good'un, so since then I've stuck to heavier grades. The engine is currently in bits for a top-end refresh and new base gasket. Once I've buttoned the engine back together, and run the new rings in, I'll be shifting back to the 5W-40 for long-term use. There was no clutch slip to speak of, even though this is a car oil.

On the XJ9, I've been using 10W-40, 15W-40 with no real downside, but there's a bit of clutch stickiness there every cold start. The caution against using synth in this engine because of the starter clutch is what's dissuaded me from doing so.

 

I'm a very new rider and just getting motorcycle license. I bought my XJ750 a year ago because I always loved the bike and finally found one at the right time and right price. I've been going through the bike and cleaning, fixing as I go. After reading through the thread and the linked PDFs I decided hogfiddles has it right. I changed oil and filter using Yamalube 10w-40. Thanks k-moe and everyone else for expanding my knowledge of oils and the specific challenges of lubricating and cooling air cooled bikes. Cheers!

 

Hey Spear,
Welcome to the camp.
Strongly recommend you sign up for an MSF course...

 

Thanks Stumplifter, my course starts next Friday

 

Thank you, everyone, for your valuable contributions to this page and site. The importance of good oil should not be taken lightly. I've always been a believer of buying a quality oil regardless of the application. A close motorcycle friend recommended that I use the Lucas oil brand (10w-40 - for my XJ750) and I've been running it since I got the bike a few years ago. After looking up the specifications I found that Lucas meets all the requirements for my XJ750, which is comforting to know that I haven't been mistreating the engine. All that said, I'm a little more curious to try the 20w-50 as temperatures in Saskatchewan (summer) can be in the 70-90+ (20-35 Celsius).

 

That sounds pleasantly cool. 70ºF was the low here last night.
I'd not bother with the 20W-50 unless she's burning oil. 10W-30 and 10W-40 are both suited for air temperatures over 100ºF.

 

I am using the Lucas 10w40 as well. Seems to stand up to the heat of my air cooled Rebel so far.

 

It's easy to choose the expensive oil when you only need 1.5 litres.

 

a note about multiweight oils:

As I understand things, all else being equal, you want the ratio between oil weights to be as small as possible. For instance, measured as a multiplier, a 20W-50 oil's high-weight rating is 2.5 that of the winter-weight, which is a better ratio than that of a 10W-30 oil's 3.0 multiplier. The reason for it is that the oils are kept "stable" (not separating, et cetera) by the addition of long-chain additive compounds. Those additives are less good for lubricating purposes than the oil itself (of course, because they're not lubricants per se), and they break down over time so that the benefits you get for the oil mix degrade, which means you should ideally replace the oil more often. For those who religiously replace oil over a relatively short cycle, that latter concern should not matter.

This must be weighed (pun intended) against the benefits of a multi-weight oil, though. If you find that your bike performs better with a 15W-50 oil, and get clutch slippage or have other problems with 20W-40, you should probably just get the best 15W-50 you can get and change oil frequently (keeping in mind the needs of your specific engine, of course). I get 15W-40 for my XJ year-round, which is a slightly worse ratio than 20W-50, and much worse than 20W-40, though given my climate the 20W-40 (also the manufacturer's recommended oil weight) would be much better during the warmer half of the year, because about the only way I could get a quality 20W-40 here is by paying twenty or thirty bucks a quart to have it shipped from Japan or something like that. Luckily, I can get high quality 15W-40 oils designed for the demanding needs of commercial diesel common carrier shipping.

I won't swear that I didn't give a mistaken account of some specific technical detail or two for why you might want to take note of the ratio in a multiweight oil, but that's what I recall from some in-depth research a while back.

a note about synthetic oils:

Oils are produced from specific base stock groups. In general, if you have the option, stay away from oils produced from Group I and Group II base stocks. These are the inarguably non-synthetic oils. Group III oils are mostly mineral oil based and other highly processed non-synthetics, though Castrol won a court case a while back that lets various brands market them as "synthetic", so what it says on the bottle about being synthetic or non-synthetic is not always representative of the oil's actual nature. Group IV and Group V are inarguably synthetic oils, though, where they start with something that is absolutely not synthetic, purify some components of it, and subject them to chemical synthesis processes to produce lubricating oil, like wine from water.

Oils produced from Group IV and V base stocks are more expensive to produce, so of course most brands go out of their way to avoid giving hints of the base stocks they use. If your oil's label says PAO, though, you've got an oil from Group IV base stock, at least partially. Some oils based on Group III base stock are very good, and others are not very good, but anything Group IV and Group V is expensive enough to produce that I would be surprised to find such an oil that is not very good, because after all that money spent on synthesis there's no point screwing up the quality of the final product. Rotella T-series oils have historically been very good oils for wet-clutch motorcycles (or any motorcycles, really, as far as I'm aware), as have a couple other highly respected oils produced for the commercial diesel common carrier shipping market, because they aren't designed for cars with catalytic converters, they tend to lack higher-friction additives that mundane automobile oils often contain, and so on.

If something doesn't at least claim to meet JASO MA requirements as discussed above, though, you should probably avoid it unless you know something I don't, no matter what base stock is used (and remember that claiming to meet JASO MA without a certification seal means you're trusting the company to test itself). All this talk of synthetic oils is secondary. Only bother thinking about these things within the constraints of the advice given about oil standards by k-moe and others here, when you start getting obsessive about oil selection. It's also worth keeping mind that, beyond a particular point of quality, the price increases for higher-quality oil can be significant over the life of the vehicle, and the returns in the form of reduced engine wear and maintenance costs keep getting smaller. If you have money to burn, though, there's always a more expensive, better oil out there, somewhere.

a note about brands:

I use Rotella in my XJ, and I use Red Line in my Buell. Rotella has historically been a very well-regarded, high-quality, commercial diesel oil that works well with motorcycles, and uses an extremely low-ash formulation, one of Rotella's primary benefits. Red Line evidently uses some of the best base stock synthetic oil process commonly available in US markets.

The Rotella formulation has changed recently, which it will periodically do when emissions standards for commercial diesel common carrier vehicles change. I have encountered some mixed reviews of the new Rotellas that concern me, but I haven't yet put the oil through its paces sufficiently to judge for myself whether I detect any issues. If you want to know how diesel oils for motorcycles perform, though, keep an eye on people who race two-stroke bikes off-road. They obsess over this kind of thing.

In my experience, Red Line has never shown any sign of causing problems and, unlike competing "premium" motorcycle engine oil brands like Royal Purple (and unlike almost every other oil brand in the world), Red Line is (relatively) very open about the formulation of its oil products.

Both of these things are just brands, though. As company executives move in and out, as government regulations change, and so on, brands change, too. If you find what you think is a stellar brand, you should understand that can change tomorrow. You can trust a person, sometimes, but you can't trust a "brand", because the people behind the brand are subject to change.

Let the buyer beware.

a note about advice:

Opinions are like, well, stinky things. Everyone has them, and they all stink. In the end, choose your own priorities; learn what you are willing to put in the time to learn; and make decisions as rationally and dispassionately as you can about how best to meet those priorities. If your plan is to just ride a bike into the damned ground and junk it, because that's what makes you happy, do it (but remember you might want to choose a bike for that purpose that isn't highly valued by someone with different priorities). In that case, oil choice is far less important, and depending on the condition of the bike and the effects on the ride quality you might just get the cheapest bargain-basement oil you used to put in your Yugo. If you care about the vehicle, though, learning how these things work and thinking (clearly) for yourself are the best things you can do to help make the best decisions. Verify every piece of advice you get, when the quality of the advice is important to you.

I'm just some random text on the Internet, as far as you know.

 

That's some solid sounding information, @apotheon . Any sources you can provide? Credentials? Seems to me that you go beyond the average consumer!

 

I'll try to find one of the places I looked up such information. I can think of only one resource that's likely to be findable this long after I looked it all up, but it's a pretty good resource, I think.

As for credentials, I'm just a technically-minded pseudo-perfectionist who often overthinks things and sometimes obsessively researches stuff.

A little more info off the top of my head while I look for info sources:

If you see PAG on your label, or a reference to "polyol ester", those are both Group V base stocks, and polyol ester is the sole base stock used in production of the Red Line oil I use, making it a Group V based engine oil. A great place to find terms to use to search for information about what makes a good motorcycle oil is actually the label of Red Line 20W-50 motorcycle engine oil. If you want to know more, start searching for information about any term on the label that you don't recognize or whose importance in providing a high quality oil is not obvious to you.