7000km later, and the problem is still there really.
The symptoms : something is rattling, sounds like something clinging in the engine. It has gotten louder and louder. It happens only on load, especially uphill fully loaded. It is not a regular noise. And interestingly, now it doesn't do it all of the time. At times, it doesn't happen at all.
I have no clue would could possibly be causing that. last weekend I rode 400km without a single occurrence in the day, and then, it started up again. I've tried fuel changes, oil change, valve ajustment is correct... And it's more or less loud.
I've checked screws, all sorts of things. Really, I'm baffled. I just keep on riding... Hopefully the noise will just end up disappearing (I thought it had this weekend, then it came back, but less pronounced).
Will keep you posted... But I'd love to know : what possibly could it be? I've ruled out small-end, big end, piston slap, pinging... Although I'm no expert none of those seem to coincide. Would the lose clutch noise coincide with the symptom? On load? Surely can't be a cam chain tensioner? Or could it? Does this thing has push rods that can come lose? Again, would that make sense? I'm open to any suggestions.
Apart from the odd noise I try to avoid (I go easy on her when the noise appears), it runs a fanstactically well...