Cam chain skip?

Bought an 06 450f and I think the cam chain has skipped. Looks to me like the intake cam needs to be moved a tooth? I don't know anything about these bikes and I wanted to get a better opinion. What do you think?

Any help would be appreciated.







Welcome to TT!

Look here for common issues and FAQS. Found at the top of the YZ450F threadline.


Towards the bottom of the link, you will find a source for factory manuals. Find one that fits you and read it thoroughly.


As for your marks.... the intake does look to be a little off but so does the exhaust (ever so slightly) where is the crank mark? its possible you have the whole assembly rolled just a bit too far. As I'm sure you've surmised, the marks should be level with the top of the head with the crank mark lined up. Any issues with it starting difficult? running funny? I feel like even if you rolled the intake back a tooth it might bring the mark back too far. Which might indicate a worn and stretched chain. I replaced my timing components on my 06 about a year ago when i replaced the piston. Just for piece of mind more or less. But there wasn't any evidence of stretching. The motor has an auto tensioner so as long as its in good working order (springs when released and has tension)  you should be ok. 

Assuming that set of pictures was taken with the crank sitting right at TDC, the intake cam is retarded one tooth, and the cam chain needs to be replaced.  The wear in the chain is causing the slight misalignment at the exhaust cam. 

Thanks for the replys

Here's the crank markings. The pic is garbage but the markings line up. The bike starts and runs fine. Only issues is exhaust popping on deceleration.



Think how much better it will run when you're done fixing this.

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