Hey gang -

I picked up a Mamiya RB67 kit the other day and included was a 90mm Sekor lens who's shutter only works at one speed. The seller of the camera said it's been like that for a while and needs a spring replaced to make it work.

Can someone point out where this spring might be on this drawing?

I've taken the lens completely apart already to clean the VERY sticky shutter blades (Can't believe how much junk came off the shutter and aperture blades!) and it now works perfectly - except for the shutter speed select. The selector ring moves freely and clicks where it should. It works correctly at the "T" setting. Any ideas?

I'm very mechanically inclined and love to tinker so I would rather fix it myself instead of sending it out at the risk of screwing it up forever.