Brand new set of headstock taper roller bearings to fit:
 
Yamaha YZ 490 (1981-1988).
 
These steering bearings have been designed to replace the original bearing set on a Yamaha YZ490 for the years shown above. The sizes are as follows:
 
Top bearing sized ID25 x OD47 x WTH15.
Bottom bearing sized ID30x OD55 x WTH17.
 
All sizes in mm