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Discussion Starter #1 (Edited)
Hi!

I am starting to hear an unusual noise from the engine (15k miles)

Not at cold start but after 10 minutes of operation and fading when completely hot (but still noticable).

2015 duke (200 and 390) have an automatic oil pessure cam chain tensioner.

During (very) cold start the oil is too thick thus the tensionner push stronger than it sould the cam chain hence chain is wearing faster than it should be and as result the cam chain becomes rapidely loose (and so the ticking noise when engine is not too hot).

Are these assumptions right? Is there any other person that faced the same problem?
 

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I think the chain tensioner is a simple bring tensioner, have you been able to locate exactly where the sound is coming from? When were the valves last adjusted?
 

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Discussion Starter #3
I think the chain tensioner is a simple bring tensioner, have you been able to locate exactly where the sound is coming from? When were the valves last adjusted?
Thank you for your answer.

I had checked the manual, yes i had seen something like a "lock" mechanism in order to release tension (counter clock wise brings tension and clockwise slackens the tensionner) but i thought that this mechanism was the "basic" tension and the oil makes the final tensioning. Maybe i was wrong and duke has only a bring tensionner. If its a bring tensioner then i think if i try to tight it a little the ticking noise will go away and i will be sure that this was the issue. If i tight the tensioner more and the symptoms won't go away then its something else. People reported that some engine heads faced problem with excessive wear at cam and cam folower.

I will check it today and report the results.

Valve lash checked just 6 moths ago by my self and the KTM dealer and it was ok (just in the middle between min and max values).
 

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You can't tighten the cam chain tensioner, it is either on or off, just make sure it's not locked off, try to turn ccw lightly to make sure.
 

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If it's ok, (turn cw and feel tension) remove the valve cover and recheck valve clearances, as well as visual check for wear on cams and followers. My exhaust valves were way out 4 months after dealer said they were checked and fine!
 

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Discussion Starter #6
Mike M, i stripped the M10 bolt of the tensioner. Below there was a star shape screw (not torx) that needs the proper tool (first time i see something like this). I have tried counter clockwise with a wide and thin slotted screwdrive. Looked "locked" although i thought it took a little. I felt also this tension while trying cw.

After doing this i didn't notice that ticking sound. After 1k miles i have maintenance scheduled (engine oil and filter). I will check for cam wear, cam chaiin tensioner function and valve lash.

thank you all for your help.
 

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Discussion Starter #8
Perhaps a replacement tensioner?
sure after the tensioner is inspected. Although there isn't any inspection info at the workshop manual i suppose that a "tightened" tensioner that leaves the cam chain loose must be replaced.
 

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sure after the tensioner is inspected. Although there isn't any inspection info at the workshop manual i suppose that a "tightened" tensioner that leaves the cam chain loose must be replaced.

There is a spring on the tensioner itself, unless the chain needs replacement I would think that the only thing that could effect it would be the tensioner. Chains typically last a very long time so I don't think that is your issue. What I would be worried about the most is if the chain isn't getting as tight as it should be it could very easily jump timing cause a fair amount of damage.
 

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Discussion Starter #10
i found also an adjustable tensioner, might help if there are any issues with stock tensioner.

Mechanical tensioner should be set cold with a little ticking sound that will go away after the engine gets warm.

If my stock tensionner is damaged i might consider the adjustable one.
 

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Discussion Starter #11 (Edited)
finaly i took out the tensioner and checked his function;

Yes its an "on-off" tensionner. After removing the 10mm bolt there is a slot head bolt. By turning clockwise (cw) the tensioner is becoming shorter till there is a point that it locks at the "lock" (or off) position and you can't turn cw the screwdriver further. At the lock position the tensioner is at its smallest lenghth and the cam chain is completely loose.

From the "lock" position if you turn counter clockwise (ccw) after about half turn the spring is expanding suddenly and the tensioner is automaticaly lenghthenning till it hits the cam chain plastic guide and automatically stops expanding to the proper tension.

BEWARE: After the tensioner takes its automatic lenght you CAN turn the screw further ccw increasing the tension to the cam chain till the tensioner gets his maximum lenght (till the screw is stoped), BUT tensioner at its maximum lenght has WAY more tension than it should be (causing damage to the chain and sprockets).

In my case the tensionner was looser than it should be, so i had to turn cw till the "lock" point and than just a little ccw till the tensioner's spring auto-expands (producing a typical "tack" sound when the tensionner hits the cam chain guide). I suggest that my tensioner is ok but due to wear i just had to re-adjust with the procedure i described above (i have 15000k miles now)

I suppose that owners who are hearing a "heavy" ticking sound when the engine is hot, they must check the function of the tensioner, and specialy check the "auto-expand" function of the tensioner. It can be checked by turning completely cw and then a little ccw in order to see if there is this "auto expansion" of the tensioner's spring.

If the tensioner expands normaly but still there is that "heavy" ticking sound you can turn ccw the tensioner for a half or one turn, till the sound stops. If after 2 ccw turns the ticking won't go away, than its not the tensioner its something else.
 

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Discussion Starter #13
I suggest that it would be better if done with closed valves but i didn't check this and the engine worked well after the tensioner adjustment.

I must say again that the procedure described above, must done only if you can hear the "heavy" ticking sound from loose cam chain.
 

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duke200 I know this is an old post but I want to thank you. I had a similar sound coming from my 2015 ktm390. I followed what you did and i was able to eliminate the noise. I rode with that noise for about a week and found your post. Thanks again.
 
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