Topic: CB400F Clutch

[rz350ypvs]

I am putting my motor back together and I noticed there is some welding on the back of the clutch basket. Did it come from honda this way? It just looks like someone else did it because the welds aren't that great. I thought the rivets would be enough.





Also, another clutch related question. I have a '77 CB400F and when you are starting out in first gear, it makes a really high pitched whining noise while you are slipping the clutch. Anyone have any ideas what that is? It doesn’t slip while under load and the noise stops when the clutch is released.

[ttr400]

No it didn't come like that from Honda. The reason it has been done is there was probably too much play between the gear and the basket. Under that steel plate are 6 damper rubbers, can only be got at by grinding the rivets off. They are not available as parts.

Best to get another clutch basket, one with minimal play between the gear and basket.

I am developing a kit with new rubbers to be able to restore this problem. but it will be a while before I get round to offering it for sale.

Kevin

[Bodi]

Only in first gear?
The 400F transmission (or maybe the primary gear?) is pretty famous for whining, it's the only thing you really hear with the stock exhaust and airbox. Other than the throwout bearing there's nothing in the clutch that would whine, and that bearing would be noisy regardless of gear.

[rz350ypvs]

Thanks for the info Kevin. Will it do any harm if I just use that basket? I guess hard launches may be really hard on the clutch/transmission ect.

Only in first gear?

It only makes the noise while I am getting the bike moving from a dead stop - slipping the clutch. Once the clutch is released, it stops. Maybe I should just take the clutch cover off and inspect.