It's been awhile since I posted anything on this forum, but here goes. I've been restoring a '74 Yam TY250 (almost done). Motor is in great shape, no problems at all, just cosmetics. With the motor out I wanted to take a look at the clutch to see how worn it was. When I got it apart I saw these really strange steel disc. I had never seen disc like these before. Looked like someone had ground it a bit on the outside and made it look like a nipple. All the steel disc looked like this, except for the last one . I was told that these were stock disc and it was normal. What I'd like to know is what was the purpose of having them shaped that way?

Thanks

I don't know but it is probably the same reason why wavy edge brake discs work well too. Don't complain, those clutches work fantastically. Note that the "nipples" are meant to line up with the arrows on the pressure plate and each successive plate goes in at 120 degrees from the previous one.

The later model TY250 twinshocks have a slightly different clutch - on them all the steel plates are the same and the pressure plate works as the last inner plate.

Edited June 16, 200917 yr by feetupfun

Think i've read somewhere, possibly my manual for 250b that the strange shape has something to do with allowing them to move outwards & cut down on clutch noise.

Not really sure if its a load of sh**e or not, follow feetupfun's advice & you'll be right

Just in case,the clutch plates from the XJ(seca)400/550 are the same as in the TY 250 Twinshock.

Chrs:Mike