The Yamaha manual recommends 01 fork oil. The dealer did not have any and wasn’t sure what weight it was. I called Yamaha and the representative was not technically inclined and said “the technician said to get 01 oil”. Anyone out there know what viscosity the Yamaha 01 oil is??? Thanks for your help. Eric in WA ========== ’99 WR400, YZ timing, IMS Tank, YZ Seat, Acerbis Handguards, Scotts Steering Damper, Renthal Bars, Yamaha Full Skidplate, Devol Rad Guards, Dunlop 755F & 756R Tires ’99 Polaris 400 Scrambler –“Trail Couch, Toolbox and Lunchwagon”, ’99 Honda Z50R, ’97 Honda XR70R, Kubota L275DT and an assortment of farm equipment.