I just bought a yfz450 and its time for my 1st oil change and i was just wondering if i should use the factory oil or if ther is better aftermarket oil.

ALSO WHEN IM IN NEUTRAL AND I SHIFT DOWN INTO FIRST MY TRANNY MAKES A SOMETIMES LOUD CLICK SOUND AND OFTEN JERKS THE QUAD A LITTLE IS THIS NORMAL OR NOT. (yes i have the clutch pulled all the way in)

 

Yes, it is normal.Mine has done that since new a year ago.I use AMSOIL(synthetic) in my YFZ but the factory stuff is good to.

 

I thought you are not suppose to use sythetic oils cause they are to slippery and the clutch wont grab.

 

I've been running it for a season and a half on it without a failure.Just make sure it is for a wet clutch.