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Valve clearance might need checking, but it won’t make a lot of noise. A weak camchain tensioner definitely does - if the camchain is on the right side of the engine that’s probably it. You normally have to lift the tank and pull the airbox to get at them so if you’ve no where comfortable to do it, shop time. It’s a very easy fix though if you do have a shed.
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Had a Yam XT660X that started making a horrible noise like this. It just started while I was riding through England to get to Dover. Like 1 minute not noisy next minute noisy. I still rode it all the way to Belgium and then back to Glasgow.
Took it to the stealer when I got back and they were all like "ooh it's gonna spit a rod, don't ride it any further" and wanted something daft like £90ph to investigate.
Took it home, bought a cdrom manual on ebay and lifted the engine out myself. Opened up the casings on the noisy side and the nut on the end of the driveshaft(?) (shaft that come out the bottom of the engine and had gears on it to run gearbox, waterpump etc) had come loose.
Cost me about a tenner in gaskets and the same again to replace a fancy lock washer under the nut.
I'd never done anything more advanced than an oil change on an engine before that.
I'd have a butchers at the camchain tensioner. For the oil leak, you'll have to completely clean it, then run it somewhere clean so you can track it down.