hi all i have the cold engine knock noise seems common probably the output shaft im guessing i should try find a 12 rivet one?

I would not be too concerned about it if it is only happening when it's cold. The engine often doesn't run smoothly till it warms up and the uneven idle will often cause the knock to be very exaggerated.
If you remove the crank cover on the right side of the engine and have a play around you can get the engine into a position so as to see the shaft and rivets then you can see what state they are in by rocking the engine in 5th gear. If it is bad then movement can be seen.
My K1100 is fairly noisy when cold and they all have the 12 rivet shaft. It can just be general engine noise till the heat get in and the clearances take up a bit.

Thanks for the assurance Rick, I get the impression that from reading around it always happens

Hi newbie
Just out of interest, what engine oil are you using?
Is the knock always there or does it come and go?
Cheers

only there when cold havent got it registered yet dont know what oil is in it but will be changing it anyway

k100newbie wrote:Thanks for the assurance Rick, I get the impression that from reading around it always happens

It is fairly common. Many of them will rattle for all their life and some get so that they need fixing with the 12 rivet shaft. Keep an eye on it and if it does get worse over time then action needs to be taken.

k100newbie wrote:only there when cold havent got it registered yet dont know what oil is in it but will be changing it anyway

Back when I first bought my old girl I happened to be speaking to a retired BMW m/c mechanic who said not to worry too much about the noise. The PO told me the oil had been done but after a few weeks I decided to change it any way. The old oil was very black and seemed thin. With the new oil (semi-synthethic) the noise very nearly disappeared. I've recently changed to full synthetic and it's a little quieter again.

RicK G wrote:

k100newbie wrote:Thanks for the assurance Rick, I get the impression that from reading around it always happens

It is fairly common. Many of them will rattle for all their life and some get so that they need fixing with the 12 rivet shaft. Keep an eye on it and if it does get worse over time then action needs to be taken.

cheers for that, i notice you have an sr500 ? i was looking after one for a while we had it nicknamed the clown bike