New roadstr,synthetic 20/50,older roadstar 10,000,miles or more conventional 20/50.
The oil capacity of a Yamaha Road Star is 5 quarts. It is recommended to change the oil every 5,000 miles for optimal performance.
The motor oil capacity of the 2002 Yamaha Road Star is 5.3 quarts. However, it is recommended to use 4.3 quarts with a filter change or 3.9 quarts without a filter change.
4 to 4.5 quarts ( measure what u took out and put that back in)
Road Star Clinic has an excellent 'how-to', complete with pictures here: http://roadstarclinic.com/content/view/158/116/
yamalube factory Yamaha
Yamalube motor oil
the manufacture specified oil weight is 20/40. i use only Yamaha oil as it is designed for Yamaha products.
fork oil capacity for a 2009 yz450f is 6.73 us oz recommended oil is Yamaha suspension oil "S1"
10w-40 is recommended
When owning and maintaining a recreational vehicle, it is important to know what type oil is needed to run it smoothly. For a 2003 Yamaha Raptor 80 SAE 10w40 type se motor oil is recommended.
Everyone will probably give a different oil here. I personally only use AMSOIL 20-50 synthetic for my Yamaha.
The oil capacity for the Yamaha Big Bear 400 is 3.2 quarts. It is recommended you use 10w30 oil in the Big Bear.