I just looked it up for your bike and the part number came back as 90179-20011-00 for the nut. Also make sure to get the washer, its critical as a spacer; 90201-20023-00
DO NOT go to Home Depot! this is a specialty nut. Yes, it's just metric threads, While home depot isn't going to have anything that fits you could probably find one somewhere that will physically thread on however it won't have the shoulder for proper spacing or the lock ring to peen it onto the output shaft. For a sprocket nut I would never use anything other than the actual Yamaha OEM part. There is too high of a risk of messing up the output shaft or bearings, or having a chain jump and smack a hole in your case.
Unfortunately I am too new here to post links apparently so the best place to look for accurate part numbers is go to shopyamaha.com
most all of the sellers that have OEM diagrams are pretty good but I have seen some errors before so I always double check.
Try going to your local Yamaha shop, There are only about 4 or 5 different sprocket nuts and washers that cover all of the late model Yamahas most likely they will have them on the shelf, and usually within a few $ of what you can get it online for. It also never hurts to support your local shops.
Last edited by AutoPilot; 05-16-2020 at 03:52 PM.