[Yamaha-R3]

As per the manual Front Fork - Chek Operation and for oil leakage.
Replace if necessary.

Do you know if this should be replaced every 7000miles/12months?

 

[pattonme]

If you're doing 7K miles a year then sure. The vast majority of US riders barely rack up 3000/yr so change is recommended by 10K miles or 3yrs. You can change as often as you feel like. I get forks sent to me that are 10+ years old and have the original oil in them.