Hey, i'm sure someone here can help me out here, should be a pretty easy question i hope. So I just got a used R1 to replace my totalled ZX7. I'm gonna do an oil change on it but it's manual states it needs either 10w30 or 20w40 oil. The thing is I have some unused oil left over from my ZX7 days that is 10w40 (and a litre of 20w40). Am I wrong to assume that it won't harm the R1's engine if I put in 10w40?
Also, would I be stupid to mix the 20w40 and 10w40 oil?
Thanks for any help guys.