New to the 450 - valve adj question.

Hey everyone, I just bought a YZ450, it's an 07.

I have searched and found a few threads, but nothing to answer my question, maybe missed it, but are there places where I can learn more about adjusting vavles? My bike didn't come with an owners manual. I am going to order one, would also like to get a shop manual. I am not sure if the prev owner has ever done it, or what to check to see if it needs it. '

If someone could help me out it would be great.


well its not a very hard job at all get a feeler gauge set and start from where it says it suppose to be and go up or down from there on the feelers. it seems scaring but is a very easy job and it probably wont be out of spec. they yamaha has a very good design. and make sure its all at tdc. and what you check is the space between the cam lobes and the bucks.


If you look in Common Threads (you know, the thread in the index the says, "Look here first") you will find a link to download a manual free. The Yamaha owner service is very nearly as good as the shop manual.

One thing you will learn about adjusting valves on YZF's is that it's almost never necessary, although a handful of '07's did come through below spec brand new.

You can, in the meantime, use this procedure: (also in Common Threads)

The one thing about the Gen2 YZ450 ('06 and later) is that the upper motor mounts cannot be worked around. Just remove them.

If you do adjust the valves, you'll need a good torque wrench, preferably a 1/4" model reading in inch pounds. Cam cap torque is CRITICAL.

Specs for your bike are .10-.15 MM for the intake, and .20-.25MM for the exhaust (that's .004-.006", and .008-.010" in English).

Forge ahead and check them. It's probably as far as you'll need to go.

Thanks guys, the thing runs and sounds perfect, want to make sure it stays that way.

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