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Timing chain tensioner spring let go

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Hi, i was out on my 2011 yz450 a few weeks ago when it all of a sudden made a slapping noise and stopped. I couldnt kick it over after that.. it had seized up. Got the bike home and started investigating. I first ripped the cam cover off and checked for any thing obvious and found the timing chain was loose.  I Removed the tensioner and found the spring had broken causing it to let go and let the timing chain come loose. Long story short, i temporarily fixed the tensioner (put a bolt through it so can manually adjust tension) turned crank over a few times with no issues. Reset timing and put it all back together. The crank tur s over fine and i can kick it over no problems. But i cant get it to fire. Bike has plenty of compression. I checked timing again and went back over everything. Checked valve clearances. They were slightly out of spec ( .01mm looser on both intake valves) exhaust clearances in spec. Drained and replaced oil, oil was fine no metal or anything suspicious in there. Im a bit stuck as to where to go from here. So was wondering if anyone has any ideas? 

Thanks alot.

Tom

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Got gas? Gas is on? Has a good blue spark? Pitch a wire or forget to plug something in? If it has compression your missing a correctly timed spark or fuel. Kick it over and then pull the plug. Wet or dry? Dry means your not getting fuel or it's being burnt. Wet means your not getting a spark.

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18 minutes ago, tommyr21 said:

Hi, i was out on my 2011 yz450 a few weeks ago when it all of a sudden made a slapping noise and stopped. I couldnt kick it over after that.. it had seized up. Got the bike home and started investigating. I first ripped the cam cover off and checked for any thing obvious and found the timing chain was loose.  I Removed the tensioner and found the spring had broken causing it to let go and let the timing chain come loose. Long story short, i temporarily fixed the tensioner (put a bolt through it so can manually adjust tension) turned crank over a few times with no issues. Reset timing and put it all back together. The crank tur s over fine and i can kick it over no problems. But i cant get it to fire. Bike has plenty of compression. I checked timing again and went back over everything. Checked valve clearances. They were slightly out of spec ( .01mm looser on both intake valves) exhaust clearances in spec. Drained and replaced oil, oil was fine no metal or anything suspicious in there. Im a bit stuck as to where to go from here. So was wondering if anyone has any ideas? 

Thanks alot.

Tom

There is no way you could know this without doing a test, and better a leak down test.

The chances of you NOT bending a valve under these circumstances are very slim

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Cheers. I checked spark, checked fuel and everything. Been over everything a few times now to double check myself. Might have to do a compression test on it next.

1 hour ago, Jw7054 said:

Got gas? Gas is on? Has a good blue spark? Pitch a wire or forget to plug something in? If it has compression your missing a correctly timed spark or fuel. Kick it over and then pull the plug. Wet or dry? Dry means your not getting fuel or it's being burnt. Wet means your not getting a spark.

 

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1 hour ago, THE KRAN said:

There is no way you could know this without doing a test, and better a leak down test.

The chances of you NOT bending a valve under these circumstances are very slim

Compression test will be next option i think. 

I would of thkught valve clearances would be drastically out if id bent a valve. Is there a way to check? I suppose it will mean pulling the head off and stripping it down?

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4 minutes ago, tommyr21 said:

Compression test will be next option i think. 

I would of thkught valve clearances would be drastically out if id bent a valve. Is there a way to check? I suppose it will mean pulling the head off and stripping it down?

yes. do that. 

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