The oil thickness at 50 degrees is not going to make any difference at start up if it's 20 or a 5 viscosity.
You're dead wrong brother.
Nope. We're not talking about sub freezing temps here. You don't seem to get that.
Starting an engine with 5 or 10w is not going to provide any better protection than a 15 or 20w at 50f degrees. Those number come from testing done at 0F, 32 degrees below freezing. The purpose of those charts was to show that there is ZERO difference at 50f-10c. Have a super night! I was out riding all day and not worrying about the smallest of details. How about y'all??
We're not talking about sub freezing temps here. You don't seem to get that.
Of course I get that; nobody sane rides at those temperatures. What you don't get is thinner oil it thinner all the time. It doesn't become thinner magically at those temperatures. It can flow lower because it's thinner when cold (and cold could be 90ºF).
And Evitzee, no, oil grade/thickness has nothing to do with the ability of it to cling to metal surfaces. That's something fully synthetic oils of any grade can do. And the quicker you have lubrication when cold, the less of a chance of metal to metal contact. And THAT is exactly what a thinner oil can do . Finally, recommendations are made with many things in mind, and also with available grades from their own brand. For instance, Yahama recommends leaving oil in there for as many as 8K miles. Do you do that? Didn't think so. If you write a manual recommending an oil grade that will last 8K miles, then you have to go a different direction than what it's ideal for the motor. Viscosity will break down for sure after so many miles and a tranny churning the oil in there. So you have to recommend thicker oil. But if you won't leave it that long, everything changes. And since Yamaha doesn't make 5/40 for motorcycles, never expected to see that recommendation anywhere. Plus nobody made 5/40 motorcycle oil until very recently, so also don't expect it to be mentioned on ANY manual.
And now it's time to listen to Exuptoy. I never expected to change the mind of the above members, but now that basically all the myths were discussed, hopefully will encourage other younger owners more open-minded to do their own research, and reach their own conclusions based on what makes sense for them and of what they read. Manufacturers not always make the correct recommendations simply because we don't follow all the criteria for those recommendations. And that goes for the subject (break-in) as well. If somebody doesn't want his bike to last a long time, they can break it in any way they see fit. Manufacturers aim for maximum life, rather than maximum power. I'm signing off this thread.
Post by papawheelie on Nov 14, 2018 12:43:43 GMT -7
Well, gosh darn it, there you have it! It turns out that we're all right! Who would’ve thought! Break in your machine however you want, and use whichever oil you want...it just doesn’t matter a whole bunch.
Of course, we can’t have all this agreeable peace and love! So, what shall we fight about next? Spark plugs? Fuel brand and octane? Haha. 😉
Out of interest, I’ve just had my 600 mile service carried out at my local Yam dealer and it appears they do actually make fully synthetic lube from Yamalube in 10/40 flavour. I kinda found it strange when I read earlier that they recommend 10W40 but don’t sell it?
Last Edit: Nov 14, 2018 18:25:00 GMT -7 by exuptoy
It won't change the true believers who think the guys who actually designed and built the engines are knaves, fools, and bumpkins who don't really know what is best when it comes to break in and oil specs.
I'll still break my engines in per manufacturer specs.
I mostly do it by the book too, at least the first 600 miles. It's good to see a video with some technical proof, but you just can't extrapolate from 600 miles the rest of the life of an engine. In addition, like he said at the end, there're many other components that also require break-in, namely the tranny, that they didn't check. At any rate, not surprised at those findings; most wear occurs at start-up, due to lack of lubrication, not because improper break-in. And that wear starts showing later in the life of the engine. The most important engine break-in aspect IMO is to seat rings properly, to minimize oil consumption, not to avoid wear (as proved in that video, not much difference). And that takes place much sooner than 600 miles. But the tranny gears take longer, but not 1,000 miles. And yes, oil always makes a difference, and it's important to use the correct one for riding conditions, but some ignorant people here think they're the same, when it should be obvious to any smart person there must be a difference, but rather than find out what it is, just make stupid comments like a certain world leader. Ha ha. Guess ignorance is bliss, after all. Signing off this thread.
Bottom line, there is no downside to following Yamaha's recommendations for break-in. And as long as you use a JASO MA full synthetic oil you'll be fine. If you use a different weight oil than Yamaha recommends (10W-40 or 15W-50) that's ok, too. It won't make any difference in performance of the engine or longevity. Call me ignorant for that view but in over 50 years of riding/driving I've never had an engine failure or even an engine that used oil. It really doesn't matter as long as you stay within spec. I'm done with this thread as well, it's just gotten into a circular argument of nonsense challenging the manufacturer's recommendations.
Last Edit: Nov 17, 2018 15:53:03 GMT -7 by evitzee
I'll still break my engines in per manufacturer specs.
Blah blah blah blah, same thing over and over and over blah blah, oh and blah blah blah, I love to beat a dead horse, it gets me off blah blah yak yak yak, blah blah. I think I know it all....blah Edit: Oh yeah,"hehe"