We supply fork oil from three different brands depending on stock.
 
If your FJR has Hyper-pro fork springs fitted we highly recommend buying hyper-pro fork oil.
 
The oils we supply are the closest specification (measured in Centistokes) that we can get to Yamaha /Ohlins fork oil that is recommended for the FJ11/1200 and FJR1300  without the extortionate price tag.
 
We recommend changing the oil every 8000 miles on the FJ and every 12 -18000 miles on the FJR1300 as the oil loses its viscosity over time and gets contaminated  with metal swarf that ultimately damages the forks internals. The oil also gets broken down by bacteria and the gases given off by this can lead to  unwanted pressurisation of the forks. 
 
You will need a 1L bottle for a FJ11/1200 and two 1L bottles for a FJR (Hyper-pro fork springs only requier one 1L bottle of Hyper-pro fork oil)