Best fork oil weight for 99WR's?

Hey all, I'm replacing my fork seals and am wondering if I should switch to a different weight and or manufacters fork oil? I've seen on this forum that the Yamaha 01, the stock fluid, was 2.5 weight. However I just talked to Baja Designs and they told me it was 5 weight. Does anyone know for sure?

I've also heard the best thing I could do was move to 7 weight, but I'm not sure that would be the best idea. I figure that that will make it stiffer but it will also slow down my rebound. Anyone have an opinion?

Oh, I weigh about 210 and ride 90% trails, 10% MX and am fairly agressive.


Hey JJ,

Have you put any thought in heavier springs? Someone else in your weight category put in heavier springs and was very happy. Food for thought.

JJ, this may not help you at all but Im about the same weight and I ride about the same trails/mx as you do.

If you know somone that has a YZ and is fairly light, talk them into swapping springs with you. I did, and it has helped a bunch.

I could probably go even stiffer but for now its working out for me and for him.

Best part is it didnt cost anything.

As far as the fork oil goes, I use Spectro Golden (light 7.5 I think?) It seems to work fine and its definatly not too stiff.


Darin from Missouri 1999 WR400F

I agree guys I do need to get a heavier spring in the back. I think I remember being told though, that the fork springs on the 99 WR are about right, is that wrong? What I'm trying to do is learn about the suspention and learn what I like and dont like before I spend the money to get it worked over.

I gotta say though I'm pretty disheartened, I have yet to find anyone that seems 100% compitent with WR suspention. I've talk to quite a few "Big" names in suspension and they all seem to be clueless, telling me incorrect specs about the stock components and exact oposite information as the next guy... what gives...

Like I stated earlier I've been told that 7 weight oil is the sh** by a few guys and others have told me it is totally wrong!!!!!! What is a guy to believe!!!????



The heavier the oil, the slower your suspension will operate. If you have your fork compression only a few clicks out, I'd say 1-4, you could go to a stiffer oil. I was running my forks at 18 clicks out!! Unfortunately I had so much dive it was dangerous. The forks were supple off the top but just blew through the mid stroke. For me, raising the oil level may prevent the bottoming, but I am guessing the forks would still dive. I have 2.5 # oil I am sticking in my forks, I just haven't gotten around to doing it yet. I will be putting in stiffer springs and I weigh 170# out of the shower. Remember, the stiffer oil will affect your rebound damping also. Too stiff of an oil will cause packing if you have run out of rebound adjustment. Packing is when your suspension cannot rebound quick enough before you hit the next bump. Obviously, there is a happy medium in settings and performance. Check your suspension settings prior to doing any major changes such as oil weight.

Either Dirt Rider or MXA did a thing on forks in the last 3 months. If you can get your hands on the issue, it will help you greatly. Once you understand how the different settings effects everything, it is so much easier. Also, if you adjust one end, the other will be affected. Sometimes it is just easier to have a REPUTABLE shop take care of it. This doesn't necessarily mean Race Tech or Pro Circuit. The general problem with the TOP shops is they set it up too stiff. Be sure and tell them your riding ability and what you ride.

I wish I could help you more, JJ.


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