demons88welcome to the ownership. remember to use mineral oil until at least until 5000km.
If you get free service, just use the Yamaha oil. Otherwise, look for Castrol. For more, check Page 1.

My personal favorite is getting a 5 liter bottle of Rimula R3x and use until finish, for best economy.
If can find Rimula R4x also ok.

I last had R3x in my RGV gearbox, use for 2000km, then store for one year. When drain, it is still clear and gold color.
[attachmentid=4353602]
Have you been following good service practise?
If not, then you should, before it breaks down on you.

my y15zr has issues. here are the chronologies.

1. installing givi box with the heavy duty rack. no problem.
2. last week motor handle goyang like crazy if i release both hands. almost terbabas.
3. didnt check the rim, but i go change the front bearing.
4. still goyang. so i change both tyre (havent change since bought, 25000KM already) to corsa r26. 80/80 front, 120/70 rear. while installing the new tyres, the pomen told me front rim has slight gelong.
5. new tyre feels so smooth but now i have to fork out more money for rims. i was told rims are sold in sets, both front and rear together.

cool story bro.