Hi Steven,
Finally she is back on the road!
Congratulations! I guess you did the right thing - the heads of the small Fours are easily damaged and sure enough one of the POs just was not aware of that fact (friendly spoken).
So now onto a cautious break in period and then onto the clutch to get rid of the idle rattle.
If anyone knows a good thread or link to a supplier for what you need to do to minimise it that would be really appreciated.
The most common cause of clutch rattle is synchronisation of the carbs - or the lack of it. So the first thing to do is to give her a proper tune up. I'm using
http://www.carbtune.com/ and am very pleased with it.
You should be able to get rid of the rattle above 1500RPM. If that's not the case, your primary chain is likely to be stretched to an extend that justifies replacement. While you've got the primary shaft out, you should inspect its bearings and replace them if you feel that they have play. Replace the rubber dampers inside the sprocket on the primary shaft as well (stake the screws of its housing!).
The clutch can develop loose rivets that add to the shatter. I have no experience on how to deal with them.
And also the axial play of the clutch basket might need adjustment using shims (25mm inner diameter IIRC).
After reading several threads about primary chain replacement, my conclusion is that you cannot fully avoid clutch rattle below 1500RPM. It might disappear with a new chain installed but will come back soon because the chain has no tensioner unlike the 650 or 750. So if you can keep the noise to revs below 1500, I'd live with it and make sure that the engine stays tuned. There's one problem with a very stretched chain: It's rubbing on the main oil channel to/from the oil filter and can eventually pinch it. So if synchronisation is not going to help, you should open the crankcase in order to examine the extend of chain wear.
The primary chain and damper rubbers are available at David Silver spares:
http://www.davidsilverspares.co.uk/CB550F1-SUPER-SPORT-1976/part_41428/http://www.davidsilverspares.co.uk/CB550F1-SUPER-SPORT-1976/part_5023/ (8pcs)
You should also have a look at Dutch located
http://www.cmsnl.com/honda-cb550f1-super-sport-550-four-1976-england_model17113/partslist/E13.html#resultsThey are more expensive but also stock more parts.
Just one more advise: Buy new snap rings and take care about their orientation:
http://forums.sohc4.net/index.php?topic=86429.msg972461#msg972461Cheers
Carsten
