Hi there my 08 XTX don't sound so sweet.
Smooth running motor up until last month.
First thing to catch my attention was a metallic buzz/rattle at mid revs,
followed after a week or so by what I thought was pretty loud tappet sound.
(I know they can be fairly loud, but this caused me concern.)
So I changed oil and filter. Then I adjusted the valve clearances, they were mostly too tight.
This made a difference but not really what I would call fixed.
Next day the tappets seemed loud again, so I checked again, ok maybe at the loose end of the tolerance so I made very small adjustments to exhaust side.
All adjustments with a cold engine.

Still not happy, so went to Yam shop for advice. aiming my concern at the cam-chain.
Bloke revved and listened and said sounded ok, I wasn't so sure.
Bloke said 'just general engine noise, not to be concerned, XT's are pretty noisy engines anyway' hmm.
Now I know what my bike sounded like, I ride it every day, it has suddenly changed recently.

I've looked at the cam-chain adjuster and that 'seemed' ok but I've ordered a new one anyway.

symptoms are:-
metallic buzz/rattle at mid revs.
general loose rattly sound when blippin' the throttle if stationary. and when decelerating when riding.
tappet sound much louder than normal
ALL THE ABOVE SOMETIMES CURES ITSELF - JUST FOR 20 SECONDS OR SO (reminding me that the bike used to be much more quiet) then resumes noisy operation. usually when at lights but probably only once a day.
Also a 'sweet spot' about 3rd revs when riding sounds quieter then any more throttle causes rattle/buzz.

Like I said new tensioner tomorrow, but the old one seemed ok and had some pressure against chain when re-inserting (without spring)

Would a worn tensioner cause the noisy tappet sound?
should any noise like this come and go? seems odd to me.

Any thoughts appreciated

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