The clutch basket I removed from my bike was perfectly serviceable. No worn out springs, rivets, no notches worn into the basket. Included are the back spacer, bearing, needle roller bearing and race. $150 O.B.O
Did you find the rattle? Serious question as I'm chasing one too. It seems to be coming from the clutch. Rattle disappears when you let the clutch out. Has only started recently. Was fine before that. I will pull it apart soon to have a look, but it will be interesting to see what you find.
I found that the oil pump gear/shaft turns a fair bit before it engages. It is driven off the back of the clutch basket. I suspect that the balance being out is causing the rattle. I thought I had the bike balanced, but it appears I still have a vacuum leak somewhere. I replaced the tower in the clutch cover, the rod that pulls the pressure plate, and its bearing. The bearing was OK but the other two items were worn beyond what I would call serviceable.
I seemed to find that the clutch makes the clacking noise and the chain makes the sewing machine whine. The smoother you can get the idle tuned the less clacking.
Have a listen to a Ducati dry clutch when you pull the lever in. Sounds like ten skeletons in a tin bucket.
https://www.2fiftycc.com/index.php?threads/1993-zzr-250.8957/page-4#post-113608 https://www.2fiftycc.com/index.php?threads/fzr250-clutchs.9564/
The bike has always rattled... it's always been the balance. Balanced it once and found vacuum/air leaks all over the place... did the litetek kit straight away when I bought the bike, then did the manifolds, then the vac lines. I made the mistake of assuming I fixed all the leaks with the new parts, and balanced the carbs. Still rattled. I'm going to work tomorrow to balance the carbs once more, after hitting up Aldi for some more motorcycle socks.
I have found that the removing the tubes and blanking the ports on the carb boots make it run alot smoother at idle . only downside is that had to use the fuel tap on the prime setting