Here is the video doing the valve job on this bike using a cheap eBay special valve cutting set. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-T7Yok3-2x1I.html and here is the video of the CT90 Fork Rebuild ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-5ICP2YImTfk.html