Thank you all for replying
My rule now is: Unless the noise gets louder and louder, ignore it...
If the bike goes and stops don't worry about it.
I have to say that this is not my going on suspicious sounds from an engine. I know old pieces of mechanic stuff develope sounds over time, but I feel that this one would come from a very worn, sloppy engine, which this shouldnt be.
I dont think this is a chain rubbing against the housing. Its a distinct klonk-klonk-klonk, a loud knocking sound that is felt when you touch the water pump and the right hand cover. Im not a novice on engines, but I have mostly done car repairs. Never motorbike.
If this sound was coming from my car, I would be very alarmed. Espescially as the sound reminds me of a toasted rod bearing.
So Im happy to hear it most certainly isnt a rod, that would break my heart.
Yesterday evening I read something about the bolts in the starter clutch beginning to come loose, making such a sound on idling, that disappear on reving.
What is a starter clutch and how do I check it?
Sorry but my technical vocabulary on motorbike stuff still lacks