Engine rattle?

[jimshea]

I have a loud rattle on tick over, particularly when the engine is cold. I am not mechanical, but it sounds a bit 'big end' like to me!?
I am told that these bikes make a loud cam rattle, is this true? If so, how can i differentiate between the 2 noises?
The bike is a 76 CB 570 F.

[paulknapp]

Bigend knock is more prevalent when the oil is thin when warmed up. What does it sound like when you pull in the clutch and put in gear?
Cheers, Pablo

[jimshea]

Pablo,
The noise only happens at low revs when cold, even when cold, when reved to 2-3k the noise seems to go. Pulling the clutch in does not have any effect on the noise. I have been on the US SOHC site and it seems that the noise is most likely to be cam chain rattle, which is quite common on these? Also, they keep talking about the need to 'synch the carbs'. I am not a techie so I am looking for a good mechanic local to me in Surrey.
Where are you located and do you ride a CB 750?
Cheers,
Jim.

[paulknapp]

G'day Jim, I am in OZ, ride amongst other things, a K2 750. My engine has a terrible rattle at idle, up to 1500rpm. But as soon as i pull in the clutch it stops,it is then mechanically very quiet.  I have synked the carbs the best i can using my home made water mamometer,but i think it could be sucking a little air around the rubber inlet manifolds. I believe my noise is only the characteristic clutch basker rattle??I am not familiar with other noises of these engines, so you had better get a local expert to have a listen.
 Cheers Pablo

[jimshea]

Thanks mate... I hope the weather is better there than it is here... Winter is on its way...
I will get the bike checked out, but mine does not make any noise change when I pull teh clutch in....