My trusted service manager at Sydney City M/C, Lane Cove says that Yamaha KYB01 fork oil is 5W so that's what I've used (the Motul fully synthetic version) and first ride, with some slight adjustments, was good. Job done. :)
My 2008 FZ1 has just hit 30,000kms and I'm about to change the fork oil. What is the best weight oil to use? I'm 80kg dripping wet and like a "spirited" ride. 5w, 7.5w or 10w?
I have a 2008 model with a Power Cammander V tuned by Dave at Sydney Dyno. I've done the airbox flow mod and blanked off the AIS, stripped out the Cat Converter and fitted a MIVV exhaust. I now have 141RWhp and 71ft/lbs at 5000rpm. Also dropped 1 tooth on the front sprocket.