YZ450F mystery part?!

I'm finishing up the top end on my '09 YZ450F and I can't for the life of me figure out where this little spring goes. I searched parts schematics and the service manual with no luck. Anybody have a clue what it is, and/or where it goes? I think I remember pulling it out of the head or jug somewhere but it was so long ago I can't remember.


ImageUploadedByThumper Talk1426346704.826441.jpg

Does that bike have an auto compression release?  If so, it looks like it could be a part of that, there is a spring in there in the head for that function.

The decompression mechanism is on the exhaust cam, so I don't think that's it. Thanks for the quick reply though.

Timing chain tensioner maybe?

Nope, not that.

Post in the yz450 forum and grayracer will probably know right away

Plunger assembly from hot start cable?

Well i just solved the problem haha. It turns out it was the internal spring off of a female air hose end, and it somehow got tossed in my parts box! Makes feel pretty stupid haha, but thanks for the replies!

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