Yz450f dropped and won't start

I'd stick with the gytr off road flywheel, its superior over external flywheel weights that bolt onto the stock flywheel. The gytr simply replaces the stock flywheel.

Ok, so when I install my cam chain how do I make sure I didn't turn the flywheel with taking it apart? Or should it line itself up when I line up the timing chain?

No, it won't line itself up.  If you have the flywheel off, turn the crank to where the slot for the Woodruff key is straight up toward the cylinder center line. Verify TDC with a screwdriver or such down in the spark plug hole.  If you grab the crank sprocket with a pair of pliers (carefully), you'll notice by turning it slightly left and right that you can actually feel where Top Dead Center is; it's very easy to move the crank 3-4 degrees in either direction.


If you get the timing one tooth wrong, it will be off by 22.5 degrees, the amount that one tooth on the cam sprockets is equal to in crank degrees, so don't be too concerned about being precisely at TDC.   A mistake like that will be obvious, and the timing will be correct if the crank is with 4 degrees of TDC in either direction when you set it up. 

Thanks a lot for all the help so far. So I got my bike back together an running, but its making a loud knocking so I'm assuming I got bent valves (or no?) or is there maybe something else that could b wrong that would make that noise?

And if I replace the valves, can I just change the 2 exhaust valves or do I have to do them all? And what else should replace other than the valves themselves? And what's better titanium or steel valves?

If it had bent valves, it wouldn't run.


"Loud knock" could be normal or abnormal, and if abnormal, any number of things can cause it.  Take it to a shop and have someone with and educated ear take a listen.

So I rechecked my my valve clearances and the one was 0.18 mm, so I fixed that and now the knocking is gone. So thanx for all the help.

So my bike is smoking now tho, should I be worried about that?

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