oil

KLOTZ synthetic is a great premix oil to use. doesn't even have to be synthetic that's just what I prefer. I have been using it for years and never had anything bad to say about it. And I never had an engine lock up since ive started using it.
 
I always have, and always will use a Castor based oil.

Any oil that is designed for air cooled motor cycles, but not for weed eaters or chainsaws.

Choice of oil is an operator preference, one will be informed by a multitude of people that the oil they run is the best.

Provided it is mixed at the correct ratio, and the jetting is spot on, then any good quality 2 stroke oil is the best.