Best full synthetic oil in 09 yz450f?

That's a bit of a two-part myth there, at least partially so.

For one thing, the 75% quote is used to describe normal wear on an automobile engine, and 75% is a bit of a conditional exaggeration. Certainly, cold staring is a problem to be dealt with, but the wear that occurs during startup is not 3 times that which occurs in, for example, the top 8mm of the cylinder during high RPM operation under power in a typical MX four-stroke. Also, the oil has to have the ability to prevent failures under extreme conditions that would not be considered normal wear events.

Secondly, the cold start protection comes from the anti-wear additive package, which can be the same regardless of the base stock the oil is made from, and from using multi-grade oils such as 10w-40's that are thin enough at low temperatures to flow freely and quickly through the oiling system. Multi-grades are also available in both synthetic and natural petroleum based oils.

Synthetics, per se, are no better at cold start protection than petro oils unless you specify Group V esters, which do have the advantage of polar behavior. That is to say that the oil film has a tendency to be attracted to and cling onto metal parts to a greater degree than other oils, so they tend not to drain off completely over time. In other premium oils, the anti-wear additives pretty much take care of this without relying on polarity, but it's a nice feature, nevertheless.

Then why would you not use a group V oil?

I did read that Amsoil was originally made from a group V but now from a group IV. Wonder why they would change?

As far as I know, no Amsoil product was ever made from an ester base, but if it was long enough ago, one of the major drawbacks to esters was that they were quite hygroscopic. That is, they attract and absorb water. By that, I don't mean simply that they will suspend water that way any detergent oil does when the two get put together, I mean that if you expose an ester to air, it will eventually become water contaminated, like brake fluid does, by drawing water to it from wherever it may be. This was the reason a lot of blenders preferred PAO (group IV) synthetics to esters early on. Even though most of the problem has been addressed, it's still true to some extent, which is one reason everyone doesn't use them.

The other is that esters are more expensive, and most blenders feel that there is not an adequate advantage to offset that. Any engine that has been run more than a few hours on any oil containing a reasonably good boundary lube package (anti-wear additives) generally is well enough protected that it doesn't need the polar behavior of esters.

I don't change the filter every time, but every other time. The time I don't change the filter I use a non-synthetic because it's not a complete oil change and I'm a cheap bastard. Yes I save 6 bucks on a $8k dirt bike. This is automobile thinking...never mind.

You can service the filter every other time if you're OK with that, but with a Scotts you don't really have an excuse for it. Using a different oil is weird (sorry). Just pick an oil you're comfortable with and use it.

belray works just fine

4t stuff work great

I've always used yamalube full synthetic and based on the internals of my engines I'll never change unless the oil changes quality. And as for rcmxracing mixing oils thats dangerous territory. I'm not speaking from personal experience but a friend of a friend mixed some non-synthetic and full synthetic in his snowmobile and the oil gelled and wouldn't inject and he grenaded the engine. As for how much truth there is to that I don't know but I wouldn't risk it.

... as for rcmxracing mixing oils thats dangerous territory. I'm not speaking from personal experience but a friend of a friend mixed some non-synthetic and full synthetic in his snowmobile and the oil gelled and wouldn't inject and he grenaded the engine. As for how much truth there is to that I don't know but I wouldn't risk it.
The only risk in mixing engine oils that I'm aware of is in mixing castors with petroleum or synthetic products. What he's doing is safe enough, but it's still weird.

OK, so I checked the TT store and the Scotts Stainless filter is no longer available... What is a good option for a stainless oil filter??

get em cheap off ebay

OK, so I checked the TT store and the Scotts Stainless filter is no longer available... What is a good option for a stainless oil filter??
If the Scotts is not in the catalog, call the TT Store toll free and ask for it. The can get you one.

The "cheap" ones on eBay are usually just that.

The only Bel-Ray oils I've seen come through were EXS and V-Twin. V-Twin was barely a 20w-50 to start with, and dropped into the 40 range during the first of 4 test cycles. EXS lost viscosity in each cycle, but remained a 40 weight the entire time. It generally did OK.
That wouldnt be a test conducted by "Amsoil" your referring to would it be???.....Just funnin with ya Gray......I just read the same report. Funny an Ams oil test would have Amsoil finishing on top???

Just funnin.

just got a new 450 and decided to run mobil 1 4t, when i was buying it I also saw that castrol makes a 4t, the only difference i could see when looking at them was the mobil 1 is jaso, and the castrol is jaso2, what is the difference?

MA2, as with MA1, is a wet clutch safe oil standard that allows certain oil chemistry and characteristics that were not allowed under MA. That particular difference is not very large.

The greatest concern with most MC oils is whether they hold up in the trans, and no one outside of Amsoil has any labeling info that suggests anything about that. MCF and MCV are labeled as meeting API GL-1. JASO-T904 is supposed to cover this to some extent, but in practice, it doesn't.

Outline of the Standard

We've run cheap dino Shell rotella for years with no problems. It's also Jaso MA approved now. The oil gets dark quickly because it is a high detergent oil, but that does not mean that it is bad. Upon disassembly of my KTM the engine was spotless.

The oil gets dark quickly because it is a high detergent oil,...
All premium and even mid grade oils are "high detergent". When oil darkens, as opposed to just getting dirty, there is one of two reasons for it; either the oil has had a chemical response to fuel contamination, which occurs on every cold start, or it has oxidized to some degree. The first is not necessarily bad as long as the oil is heated enough to evaporate the fuel that caused the darkening. Oxidization is bad, however.

Rotella's downfall is it's inability to remain at its rated viscosity for more than a very few hours when exposed to the fluid shear that occurs in the transmission.

MA2, as with MA1, is a wet clutch safe oil standard that allows certain oil chemistry and characteristics that were not allowed under MA. That particular difference is not very large.

The greatest concern with most MC oils is whether they hold up in the trans, and no one outside of Amsoil has any labeling info that suggests anything about that. MCF and MCV are labeled as meeting API GL-1. JASO-T904 is supposed to cover this to some extent, but in practice, it doesn't.

Outline of the Standard

Redline oil holds up to trans. and is a group V oil. Enough for me and many others. They are not part of a multi level marketing game either.

Redline oil holds up to trans. and is a group V oil. Enough for me and many others. They are not part of a multi level marketing game either.
I assume you have some documentation of Red Line's shear stability. There are a number of oils that will retain their viscosity in a gearbox, and in fact, the number of oils that are capable of it is increasing as market awareness of the issue increases. There are at least 3 times as many good MC blended oils that will stay in grade for a respectable length of time as there were just 6 years ago. A UOA of your own oil will certainly tell the story. The superiority of Group V vs. Group IV is arguable.

As for as the veiled dig at Amsoil, personally, I couldn't care less how the oil is marketed. It has no effect on me one way or other. It's a good product available at a reasonable price*, and I don't sell it, I just buy it, so I don't care how they run their business.

That being said, I find that with Amsoil's recent price increases and the fact that I don't need as much of it since my son sold his bike, Mobil 1 Racing 4T and V-Twin are now available at a lower cost. Since the two are functionally equivalent, I'll be using M1 for the foreseeable future.

*Ordering Amsoil products as a Preferred Customer entitles you to a roughly 30% discount off retail, but requires a $20 annual membership fee. That and the shipping have to be taken into account when finding the true per quart cost of the oil for comparison. They do also sell Twin Air and NGK, and you can get significant discounts on those as well.

I've been running Mobil 4t or the reg. synthetic in mine for 3 years now (change oil every 8-10 hrs.) and shifts like a dream and no problems. I ran Rotella T (blue bottle) in my RR bikes for 4 years (changed oil every 1k race and trackday miles ) and no slippage. We beat the shit out of an R6 on a track, took the motor apart and looked great. I love the retards that change the oil every hr. what a waste of time. :ride:

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