Which oil do you use?

I would appreciate everyones input on this debateable issue... I have a 2001' YZ426 and I am wondering which oil everyone uses...and which one works the best? I have used Valvoline 10w 40 oil on my 4 XR's and it has worked great! I understand the YZ is a performance engine and needs higher quality oil. I only have 1 hour on my new 426 (due to Texas's rainy weather) and I talked to a local mechanic and he recommends Motul and another mechanic recommends Castrol! Aren't these synthetic oils...I always thought synthetic oils reaked havoc on 4-stroke clutches? I would appreciate any input you guys have on this issue! Thanks,



I get my kicks on a 2001' YZ426!

Friendswood, TX

Expect a wide range of opinions on this subject. With such a variety of quality lubricants available, many would be a good choice. Synthetics don't necessarily wreak havoc on our clutch. Only when you use friction modified oils do you run this risk. I use Bel Ray EXS synthetic oil with excellent results in my 2000 YZ426. I've also used Yamaha 4R and Golden Spectro syntehtic blend. I decided to go with the EXS to try and improve the shifting of my 426. Not that it was bad, but I found it to be a bit notchy and it resisited downshifting from 2nd into 1st reliably. According to an article in one of the dirt oriented magazines, there was a claim that the EXS oil could help. I find that this oil did in fact help with the general feel of shifting and I will use it from now on. This is strictly my opinion.

[This message has been edited by Boit (edited 11-18-2000).]

any high quality RACING motorcycle 4 stroke oil will work. The motors in these bikes are rather high strung, so I wouldn't use the valvoline, I've always used the yamalube 4R and been pleased, but wouldn't hesitate to use the equivalent in Silkolene or Bel Ray etc. Just make sure you change it frequently!

[This message has been edited by 426Bones (edited 11-18-2000).]

Yamalube 4R for me and no problems..


I still have half a case of Yamalube 4R left but the last few oil changes in my 426 I tried Mobil 1 synthetic 15w-50w. This supposedly has no friction modifiers, and like Boit said, this is what will cause poor clutch performance. I also believe that it offers better protection than the Yamalube.

After reading lots of tests I’ve decided that the moto-specific oil is not as good of a value as Mobil 1 synthetic, but with so many differing opinions you may want to stick with Yamalube just to be safe.

Here’s an informative article on the oil debate from Eric Gorr’s website.

Hope this helps.

Like Hick, I also use Mobil 1 15w50. I've used it since after break-in and it's worked well for me. I feel it offers good performance, price, and availability.

I've used Motul for over a year in both of my

400's and I've no pblm what so ever. I've heard good things about yamaha 4 and 4R but

I've never tried it. A friend of mine races

street bikes and he has used Motul and is now

using Belray synthetic (EXS?).

Just my 2c.


I have ran Castrol Syntec and Mobil 1 in my 400 and 426 with great results. I have just recently tried Yamalube 4R to see if it helps the grabby clutch, seems that a lighter viscosity (10W30) helped more than brand. Don't use any standard grade motor oils as I've heard they have too much parafins, detergents, etc...

The quality of the oil, aside from the additives issue (i.e. avoid certain ones), probably takes a back seat to changing it more often than you think you ought to. I would go so far as to say that if it comes out dirty, i.e. not still mostly clear looking (but a little darker colored, still clear though) then you waited too long and whether it was good or not quite as good when you started with the oil fresh becomes a moot point vs its state when you leave it too long.

So, change it real often, maybe every three or four tanks of gas (that is quite a bit of riding, actually).

Also, run mineral oil for perhaps up to 8 tanks of gas to make sure all manner of break-in can occur before going synthetic.

F-Pilot- I have used Castrol Syntec in my car/ trucks for several years with good results but it does have "energy conserving" on the label and I am pretty sure this is one thing to avoid with a wet clutch. If you go to the link in Hick's post above it talks about these additives in detail...


I use Castrol RS-Superbike and that works allright.

I am also speaking to my 76 dealer about trying the mineral path ?!? :)

What is the mineral oil thing for 8 tanks or

so? I haven't heard that before.Enlighten me!!

Thanks Mike,

Thanks for the link Hick.

Mobil 1 it is for me!

[This message has been edited by F-Pilot (edited 11-23-2000).]

[This message has been edited by F-Pilot (edited 11-23-2000).]

thanks guys for all your suggestions I will stick with valvoline until I break it in all the way then i will run Mobil 1! As for the castrol syntec don't use it in dirtbikes I have had a bad experience with it on a 96' XR200 it totally screwed the clutch plates up! But works great in my Ford Expedition and Ford Mustang! Just my 2 cents! Thanks,


Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now