Unidentified part.

[Johnny4428]

I would be some chuffed if somebody could identify this part. I had stripped a clutch from a C90 and was cleaning all parts in a tray with a mixture of diesel and petrol, and when it came to emptying out the tray in among the waste oil this clonked out of the bottom of the tray. I’m quite certain it’s not part of the clutch having checked the parts list. So can anybody identify the part. It is a mystery.

[Oddjob]

It looks like a thrust washer and isn't there one first onto the clutch shaft before the outer basket.

Does it have a slight chamfer? might be the B lock washer which sits behind the castellated nut.

[Johnny4428]

Here’s a picture of the other side and parts diagram.

[Oddjob]

Yeah that looks like the B lock washer, as you wind down the castellated nut that will flatten out and it trying to reform it's shape acts like a spring washer.

Parts book I looked at was different, what year and model is the C90.

good friend poems

[Johnny4428]

It’s a 1981 C90ZZ Ken. It’s too big to fit in the clutch recess to come anywhere near the nut and lock washer.

[Bryanj]

Have you done a filter change on a four usng the same drain tin, itlooks a bit like the washer between filter and spring, or part number 24 on the pic above

[Johnny4428]

Good call Bryan! But a good bit bigger than oil filter spring seating ring.

[Bryanj]

Cant gauge size from solo pic so no idea mate

[Oddjob]

Any chance it was left in the tray from a previous bike?

Can't spot anything like it on the C90ZZ parts book.

[Johnny4428]

The tray had been clean prior to putting fresh cleaning liquid in it. There is a chance that it was sitting in the waste drum filler from a previous job, but I could have sworn there was a clonk when I emptied it out. I am quite satisfied that it was not part of the clutch I am working on. Waiting on new springs and gaskets, will put together then and make sure there are no rattles and the clutch functions as it should. But it will have to remain a mystery for now.

[Bryanj]

has it a kickstart shaft, sometimes a washer there before case goes on

[Lobo]

… at 40mm internal dia (suggested in your 1st pic), it’s surely not part of any C90 😂

[ST1100]

Looks like one of those washers sitting between fork-spring and spacer... any such work done recently?