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Discussion Starter · #1 ·
i was riding and i have been having issues with a ticking cam chain tensioner and then i was riding today and whilst in second i heard what sounded like the snap of a chain and then the bike died on me after a few horrible noises

Im presuming my timing chain snapped. Does this mean my engine is going to be destroyed?
 

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i was riding and i have been having issues with a ticking cam chain tensioner and then i was riding today and whilst in second i heard what sounded like the snap of a chain and then the bike died on me after a few horrible noises

Im presuming my timing chain snapped. Does this mean my engine is going to be destroyed?
I'll be honest mate, it doesn't sound good. I have personally run the bike while being off by a tooth on the intake side with no damage.... But yours is a completely different situation. I tried to google to see if it was an interference engine or not, but couldn't find anything. There is a high probability that you have bent valves / knackered piston head. How many miles are on the bike?
 

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First, determane what the problem is rather than guessing.
Also, tell us what bike this is, capacity and year manufactured, number of kilometers done.
I would not recognise a camshaft chain snapping as I have never experienced this in my 50 Y+ of motoring.
 

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Discussion Starter · #4 ·
I'll be honest mate, it doesn't sound good. I have personally run the bike while being off by a tooth on the intake side with no damage.... But yours is a completely different situation. I tried to google to see if it was an interference engine or not, but couldn't find anything. There is a high probability that you have bent valves / knackered piston head. How many miles are on the bike?
6000
 

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Discussion Starter · #5 ·
First, determane what the problem is rather than guessing.
Also, tell us what bike this is, capacity and year manufactured, number of kilometers done.
I would not recognise a camshaft chain snapping as I have never experienced this in my 50 Y+ of motoring.
2017 duke 390
6000 miles
As much as it has lower miles the previous owner has abused it and it hasn’t been taken care of, thought I could try fix it up
 

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The distance run is really not any indication the cam chain should break in your case.
Take off the cam cover and have a peak.
An unfortunate occurrence I have read about on the RC forum is some riders had a cam sprocket bolt back out, causing a fair amount of damage to the head.
If you do not want to take off the valve cover you can try taking out the cam chain tensioner and try to feel through there.
When the timing chain is in place there should be some resistance when pushing in the guide.
Good luck.
 

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Discussion Starter · #7 ·
I'll be honest mate, it doesn't sound good. I have personally run the bike while being off by a tooth on the intake side with no damage.... But yours is a completely different situation. I tried to google to see if it was an interference engine or not, but couldn't find anything. There is a high probability that you have bent valves / knackered piston head. How many miles are on the bike?
Thanks, ive been thinking is it possible the timing chain has just fallen off the spockets. when it did happen i didnt hear the piston hit anything as such just the sound of maybe the chain flailing around a bit

Am guessing if this is the case ill need to reset the timing ect
 

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When a timing chain snaps, and you're pretty much sure it's the TC, chances are the damages are already done, how bad or worse depends on your luck. Eventually, you'll have to strip down the engine depending on the severity. Suggestions here would not mean a thing, unless the engine actually inspected thoroughly. Good luck.

Cheers!
VJ
 

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Discussion Starter · #13 ·
Please keep us posted! I'm curious what the cause and outcome will be.
So the engine is now out and the issue apparent, one of the valves was sitting higher than the others and had been hitting the piston, the valve had then snapped and shattered the top end pretty much, going to need to rebuild the wole top end
 

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That is a very unfortunate occurrence.
Have the valves ever been adjusted?
Any pics of the piston head, can that part be saved?
Wishing you good luck in sourcing the needed replacement parts.
 

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Discussion Starter · #15 ·
That is a very unfortunate occurrence.
Have the valves ever been adjusted?
Any pics of the piston head, can that part be saved?
Wishing you good luck in sourcing the needed replacement parts.
as you can see it needs a new to top end and cylinder, also you can see the cams are warn down, will haft to look why that happened
53383
53384
53385
 

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Is the cylinder also damaged or only the piston?
Looks like too little oil has come to the top.
If you are using parts of the old stuff, check and/or clean the two oil jets lubricating the camshafts.
Good luck with the re-build.
 

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Bad luck mate.
Looks like a lubrication failure.
[please use Amsoil]
Maybe you could find an engine from a wreck.
Maybe forum could help.
 

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Worst case scenario! Find a used cylinder head and replace also the cam chain and tensioner...

The piston and piston ring must be inspected.

Sent from my A80Pro using Tapatalk
 
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