2008 yz450f question

Hi all,

looking for some help in finding out what a 2008 yz450f came with from the factory? I havnt checked the shock yet but I tore down the forks to see what a well know company did and this is what I found. BTW, it has stock springs, and was valved for a 170lb intermediate;

Also, if anyone could tell me the technical term for some of these items that would be cool, I'm eager to learn! :thumbsup:


30x.4 <-stupid question maybe, but what is this shims function? Check valve?


32x.10 (16)











20x1.6 (2)









20x.10 (4)


20x.10 (5)

18x.10 (2)

11x.25 (2) <----seems like a pretty big crossover to me?

17x.30 (3)


8x.15 <-- is this shim here to reduce float?

I believe the float is .15 on the MV.

I run between 355cc and 360cc in the outers.

How is this setup in your opinions? Firm, soft? I run my clickers at only 3 out on the compression, and 13 out on the rebound, I like stiff forks and a fairly soft shock in comparison. This revalve was done by a well known company, thats the only reason I would like to know what the stock setup was like, I am curious as to what they did exactly. I think they were going in the right direction, but I would like the front a little firmer. Should I exchange one of those crossovers in the mid for a thinner one?, .15 maybe?

Thanks for any input in advance.

Edited by dustin183

That looks fairly close to stock but a hair stiffer. You might just need a good service/oil change to bring it back. Your using a good 5 wt right?

Thats why I was curious. It feels like they were going in the right direction, just not quite far enough. I really wish I would have checked the stock valve stacks before it was sent out. But i'm confident someone on here will be able to tell me what it was. Yes I use Showa 5wt, as recommended by the company that did the revalve.

I will post the shock shim stacks when I get a chance. That is where I noticed a huge difference in performance, no more deflecting sideways off of square adges, and handles the harder hits nice.


30x.4 <-stupid question maybe, but what is this shims function? Check valve?

Exactly. The Base valve is a single function assembly. The check plate forces oil through the shim stack on compression, but allows it to bypass on extension.

Ok..... I know im a Thumper Talk newbie, so what do I need to do to get some extra help out of some of you suspension experts?? Does this help? :thumbsup:

I'm sure if you do a search you will find a STD shim stack

I don't have one on hand, but I can tell you that there's a very good chance that there were as many as 3 "standard" builds in any given year model. When I do the YZ forks, it's with a kit from SMART Performance, which is based on a complete revision of the mid-valve, so I haven't paid that much attention to how they're stacked up stock. But someone here should come up with something for you pretty soon.

I've tried searching and cant come up with anything on the 08's... I'm thinking on the BV all they did was add the 21x.10 and 19x.10, and change it to clamp on the 17? What is the purpose of the 11x.25 on the BV?

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