OIL?? YZ450F

[bigwake]

ok so i just got an 03 yz450f..dirtbike..not yfz..but i hear its the same motor..not sure if it is..either way..what oil should i put in the bike?..20w-40 or 20w-50..the bike has never been "raced" but trail ridden..so i don't know how hard..and it is all stock..any help? thanx!

[Chuck_Norris]

I am running the Amsoil V-Twin 20w50 YOu can slo stay with the Yamalube 15w40.. just dont make the mistake of putting automotive oil in it. the friction modifiers in the automotive oil will cause your clutch to fail

[bigwake]

thanx! wut i do have is some 20-40 honda high perf 4 stroke bike oil..im goin with that and see how it does..thanx again-josh