What is the best oil for my Yamaha yz 125
Any oil that meets the specifications laid out in your owner's manual. Anything beyond that is either: 1) bragging rights or 2) done to meet specific, unusual, demands of your application, and would require you to give us details before we could help you out. HTH -- Later, John 'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.
Fresh oil from a bottle is best. I suggest you use different kinds of oils in the gas tank, transmission, and fork. Altho ATF works well in forks and many are happy with it in manual transmissions, its pretty poor when mixed with gasoline. However if you have an old bike with stuck rings, ATF works well as a solvent when poured in the spark plug hole. Is also useful if one wishes to see how much smoke an engine can make.
