Believe it or not, my wife bought me my first four stroke. A Saito 82. The manual says to run "20% oil and 10-15% nitro. If this is not readily available, (I love this part) the next best selection is a high quality 2-cycle glow fuel" and it goes on to list every brand. It says straight castor is NOT recommended and a synthetic-castor mix is acceptable. The LHS has Powermaster YS/Saito 20/20 (the only fuel with 20% oil, and it is straight synthetic, no castor) and I presume that the other 20 is the nitro content. I have read numerous threads on fuel for Saito's and other four strokes. It seems that Saito owners are running just about every oil/nitro mix. I have Powermaster 10% with 18% synthetic-castor mix for my two strokes. My question is, can I use what I have to break it in, and switch to the powermaster 20/20? Or should I stay with what I have, or maybe switch to 15% nitro? I am not looking for "killer performance", I am more concerned with engine life. I am only a little confused[sm=72_72.gif]. Thanks for your help.