Light rattle comming from the top end.

Lets begin whit the happy news, passed my drivers exam this week and can now legally drive :woohoo:
But I think I might have gone to far.
I noticed a light rattle from the top end today, it does not sound very serious but still it worries me.
And the bike vibrates as a bitch. (don't think it was that bad before)
But the vibrating I recon will be gone when I syncronise the carbs (again)
(I have pulled the bridge apart since last time)

The sound from the top end on the other hand, it does not sound that serious but still I would like to know why.
On idle it's most noticeable kinda comes and goes in a set pattern (rrrrRRRRR........rrRRRRR.....rrrrRRRRR.....)
The only thing that comes to mind is the cam chain.

The thing is I can't be sure I would like to check the tensioner but I don't know how.
and anyway isn't a automatic tensioner meaning It should take care of it self?

Since now is the best time to ride here in Sweden (we don't get that many days whit nice weather)
I don't want to pull the engine apart just yet. (I have plans to rebuild the engine as a whole when winter comes)
Thinking of lifting the valve cover (need to order gaskets and those rubber seals first)
But I wonder if anyone know what it might be? maybe even had the same kind of noise?

Btw where do I find the rebuilding specs on these engines? such as wear limits on bearings, crank and so on?

Best Regards H

i would check the timing chain components.
it's seems that most of the rubber bits have about hit there age limit.


leon