alright so today i was riding on the track, and i had my 2009 yfz450r wide open... the chain popped off and stalled out.. the chain didnt bind up around the sprocket or anything. put the chain back on start it up and its knocking.  Could it be possible that a cam could have jumped a tooth or so from the aggressive stall?   please help me out,  i hope noting major! 

Is it knocking while idling or while riding it? It's been my experience that when you are a tooth off on one or more camshafts the engine won't even start let alone run.

It's knocking while idling and riding.

I would cover the basics first, How is the oil level? 

Check your head, make sure everything is tight. Valves are not the only thing in the head that can knock.


Take your valve cover off and look at the valve clearances, cam wear, and timing chain tension.


Listen to the knock closely, find where it is coming from. It could be piston slap, it could be bearings, it could be a loose valve. Anyone can play the guessing game 100 times over, but you have the right answer sitting in your garage. If you are not mechanically inclined, taking a valve cover off (and a timing peep) is not hard at all and there is nothing you can mess up just checking things.

It sounds like it's in the bottom end.. cause the timing is good... However I did notice the timing chain was a little messed up... another question I had the clutch plates out.. should the inner hub spin free while it's in neutral?

Yes the inner hub will spin free in neutral. Actually no matter what as long as the plates are removed.

OK well the inner hub only spins 3/4 of a turn and stops

How did the bike stall?

It spins 3/4 and stops but that's turning by hand, right? It is obviously spinning all the way around when in gear and riding. Sounds like you are getting closer to finding the noise. I would put a socket on the nut (inside the clutch hub) and spin it past the hard spot. Keep in mind it won't produce the same noise turning slow as it will turning fast like when it is running

Right.. and I was spinning it by hand.. so we'll see what we can make happen! I'll get back to you Marsack66

it might be time for a new bottom end. the crank could be loose if you hear knocking.

@marsack66 @suzukirider7 I was able to spin the hub around past that spot... but got hung up again at the same spot... does the inner hub have anything to do with the crank? And if the crank bearings went out do they usually cause problems on the cylinder?

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